T"His Document IS a HOLDING of the ARCHIVES SECTION LIBRARY SERVICES FORT LEAVENWORTH, KANSAS DOCUMENT NO

ARCHII CGSC FT LIEAVENWORTH KAN M1AR 3 0 1953 HEADQUARTERS FAR EAST COM~'MAND ,ACCESSION N..... PO REGISTRY MILITARY HISTORY SECT ION Japanese Research Division

IMPERIAL GENERAL HEADQUARTERS ARMY HIGH COMMAND RECORD.)~

Mid-1941 - August 1945

This Monograph may not be repro- duced. without the permission of the Chief of Military History

Japanese military command organization. Chief of Military History, Japanese Mono- graph. (1953).

T"his Document IS A HOLDING OF THE ARCHIVES SECTION LIBRARY SERVICES FORT LEAVENWORTH, KANSAS DOCUMENT NO. N-17807 C7rOPY NO. 1L

CGSC Form 160 Army-CGSC-P3-1966-20 :0Mar a 53-5M3~

Preface

Through Instructions No. 126 to*the Japanese Government,

12 October 19)L5, subject: Institution for War Records Investiga- tion) steps were initiated to exploit militar,' historical records and official reports of -,the Japanese "War Ministry and Japanese

General Staff. Upon dissolution of the ovJar.Ministry and the

Japanese General Staff, and the transfer of their former functions to the Demobilization Bureau, research and compilation continued and developed into a series of historical monogrsphs.

The paucity of original orders, plans and unit journals, which are normally essential in the preparations of this type of record, most of which were lost or destroyed daring field operations or bombing raids rendered the task of compilation most difficult; particularly distressinr has been the complete lack of official strength reports, norn al in AG or G3 records. However, while many of the important orders, plans and estimates have been reconstructed from memory and. the refore are not textually identi- cal with the originals, they are believed to be generally accurate and reliable.

Under the supervision of the Demobilization Bureau, the basic material contained in this monograph was compiled and written in Japanese by former officers,_ on duty in cormland and staff units within major units during the period of operations-. Translation was effected through the facilities of Allied Translators and

Interpreters Service, G2, General Headquarters,: Far East Command.

This Japanese Operational Monograph was rewritten in

English by the Japanese Research Division, Military History Section,

General Headquarters, Far East Command and is based on the translation of the Japanese original4, Editorial corrections were limited to those necessary for coherence and accuracy. FOREWORD

The overall preparation of Japanese Monograph No 45 was ace or- plished by the following former officers of the Japanese Army:

Hattori, Takushiro, ex-Colonel, and former Chief of 2d Section (Oerations), Army General Staff, Imperial' General Headquarters.

Takase, Keiji, ex-Colonel, and former staff member in 2d Sec- tion (Operations), Army General Staff, Imperial General Head- quarters.

Nakamra, Ryuhei, ex-Najor,, and former staff memaber in 2d .Section (Operations), Army General Staff, I nperial Gene ral. Headquarters.

In addition, specific sections of the original Japanese Monograph were assigned and written by the following former officers:

Ishiwari, Heizo, ex-Lt Colonel, and former Chief of Jaoanese Army History Compilation Section, Army General Staff.

Tanaka, Koji, ex-Lt Colonel, and former staff member in 2d Section (Operations), Army General Staff, Imperial General Headquarters.

Fukaya,.-Toshimitsu, ex-Major, and former staff member in the Department of Inspectorate General (Army Training).

Okada, Kikusaburo, ex-.taj General, and former Chief of the War Material Section, War Ministry.

Nishiura, Susumu, ex-.Colonel, and former Chief of Army Affairs Section, War inistry.

Takayama, Shinobu, ex-Colonel, and former Chief of Sub-Section (Logistics) in 2d Section (Operations), Army General Staff, Imperial General Headquarters.

Ureshino, i'ichinori, ex-Lt Colonel, and. former staff member in 10th Section (Shipping), Army General Staff, Imperial General Headquarters.

Shirai, umitada, ex-.Lt Colonel, and. former staff member in SubSection (Logistics), 2d Section (Operations), Army General Staff, Imperial General Headquarters.

In this revised edition of Monograph No h4, corrections have been inserted from the Japanese Errata on the original Japanese monograph. This had not been done in the previously submitted translation. As an editing policy, effort was directed to verifying original translation and designations, clarification of phrasing, and adding pertinent information which has become available since the original monograph was written. TAB 2~OF 'CONTENTS(

CHAPTER I -- Japanese Military Command Organization

State Affairs and "Supreme Command" Relationship ...... 1

"Supreme Command". Independence and Direct Appeali to Throne...... ** ...... 4 3

"Supreme Command" and State Affairs Concurrent Matters ... 3

. et ods for Issuing Concurrent Affairs Orders . " ...... 5

a .,P. xi~ples in Assignment of Military Officers as War Minister ...... ~..:, 4*".:. *...... ,...... "

Imperial General Headquarters and Government Liaison Conferences . . ."."" ...... ""a,...... 6

Legislative Characteristics of the - Conference ...... ,..... 7

Relationship Between the Emperor and the Conference .. «.., . 8

Conference (Council) in the Imperial Presence. ,....*. 8

Conference (Council) Agenda Example ...... 9

*QHAPTZR .I11- General 'Situ~ation Before' the War~

Military 'Preparations ...... *4...... 4.... 44444.. . 10

Training Programs *. ."4.ji# a*..0 5. 055r1)4

Expansion of National Defense Industries and Wlar M4ateriel . 16

Reserve Army Supplies Stockpile Preparations .. ... ,.. 19

CHAPTER III -- Pacific War Operational Preparations

PreparationsRelated to Outbreak of Pusso-Gerraan War . .... , 22

Preparations Related to Economic Blockade by US, Great Britain and the Netherlands ...... 224

Pre--War Estimaate of Enemy? Situation ...... 25....

* Development of Southern Operation Plan ...... ,. .... ,.... 28

Southern Army. Order of Battle Outline .... :. .... ,.,... ~.,: 29

Army General Staff Assignment of Objectives and Missions

in outhkern Operation ...... 30 ."ongkQng3 Guam and Bismarck Archipelago Operational, As- signnents and Strategy ... ,...... 33

Air Force Operational Assignments .. «...... r , ...... «...... 3)4

Line of Communication (Logistical Support ). ... " .,..... 3)4

Proposed Southern Operation Militar'y Administration 4... 44443 CHAPTER TV - First Phase of the War

PART I ---- First Stage (December 19)41 - June 1942) ...... «.. 37

Decision as to Time and Date for -Beginning War ...... 37

Summary of Orders Issued to Southern Army Commander .".....: 38 Suxmary of Orders Issued to China Expeditionary Army Commander .""""r.."«"...... * .e...... cve(o g Q 444499 3

.,.,, "Alternate Plans for Malay Attack ...... "...... , L" Orders for Kwantung Army and China Expeditionary Army ", Related to Ch~ina Incidents « «.:+ ."ho.".,.. 4 Summary of Operational Progress During First. Stage

Pdriod . * 4. *q.e.. *** ~....C9S0eS*h 4.0 J..'. Operations Planning .... h Iaa','Operations""'Burma Planning """"" "". . ., ."a . hh"4

" . ' Situation Review arid Tentative Plans "..." "«...... 45.

.. , ... P'rel'mia'ry Planning for a Chungking Operation ...... ".... 49 Aleutians, Midway and Southeast Area Operations Plans-,,,,, 5

New'Cledonia, Fiji:, Samnoa Islands and Port Iboresby Operations Plans ...... «::. : 3 Operational Conduct for Southern -Army Following Com- pletion of First Stage in Occupational Operations :..:.*55 "...... Army-Navy Central Agreement Regarding Southern Area Defense Responsibilities .. « ... *...... « 56

Establishment of Air Bases in Important Southern Zones ...~. 58

Line of Communication (Logistical Support) ,.....«...5.9.

"The hek'i~ng-iangsi Operation...... ,. .... "...... «...~ 60

.. , PART 11 Second Stage (July December 1942)...... 62

Suspension of Fiji,, Samoa and New Caledonia Operations .:.. 62

.7i'-on*Cbhaca6Aof Guadalcanal Operation * ...... ,.. «...... ,. 63

Situation Review and Plans_ (October 191s2) ...... "..67

Southeast Area Operations (N~ovemberDecember 192.2) "*...... 69

Chn e inOther . e 'perations Caused by Solomons

Difficulties ...... * ,4" .... « e' ...... 9+4:*;.::, ,*..... * 72

Miscellaneous Actions, .Duiring Second .Stag:.,* ...... s s. .... 73 Line of Communication. (Log~stical Support) .During First Phase.. ".«:....":+...... « 7

11 CHAPTER V ~ Secod"d Phase of the War (January -- August 1943)

Situation Estimate Regarding Enemy Offensive Potential ... 7

Amendments to Operational Plans for Southeast Area .. "..... 77

Orders and Operational Principles for Southeast Area .. ":. 79

General Operational Progress During Period ,..1...... 1. 81

Central Pacific Area Operations .... "".....",.I...."....".".". 83

Oresand Operational Principles for Southwest Area . ,... 81

. ... Troop Activities in Southwest Area Operations :...... 87

Troop Activities in Other Areas .. "....." "" ...... "..... r """ 88

.... Line of Comunication (Logistical Support) During> Second Phase .. f14i M "4"s ~ 1".~~*. ~ 89.

CHAPTER VI - Third Phase of the. W-ar (September 1943 - June 1914.)

PART I - First Stage (September J19h3 - February 19hh) .... 91

Situation Review and Estimlate of Enemy Potential Plans 1". 91

ArrnyGenral Staff Operational Plan Changes ... ,...4..... 94

. ~E iting international and War Conditions " *". " " . !.. "... 96

Southeastern, North-of-Australia, a nd Central- Pacific

~Areas Operational Strategy .. .. 4."...... 1 .. 98

Army-Navy Central Agreement Regarding Central Pacific

Operations ".. . . .,...... **...... *.*.4*...... 102

,Operational.. Conduct for' North-of-Australia Area . , ,...... 103

Efforts to Strengthen Shipping and Transportation ...... 4 l01'

Steps Taken to Combat Submarines ...... i"""""".". 10lO

Stegtein o Sa *s .... «...... +.. .106r

Approval of Imphal Operations ("U" Operation) ..... ".... 107

Instructions Concerning "Ichi-Go" (Hunan-Kwangsi)

*Operation .... "01"F4 ...... s*.".f1109

.Instructions for Various Other Areas .. **..***'**.*.*.***« 112

t.,. * Additional Construction and Maintenance Plans for Air

.ART II--.'-. Second Stage (Varch - June l9L .) ...... lli

Situation~and Review Estimated E.nemy Plans'"."...... ".,.14l

orho=~ztai, t TitutoS... *..:. . .. ".."...... 117

* . First and Second' Modifications of 2d Area Army Front Line. 119

iii Northeastern Area Instructions:."...... «.. "..121

Formosa, and Nansei Islands- Instructions .*...... _ 122

Southerxn Area Com~mand System Unification ...... 12L.

Change of f~'ission and Instructions for Southern Army *too* 125

Central Pacific Area Instructions .,...... 129 "4 11 "A-Go Operations in Mariana Area ...... 130

Instructions Strengthening Homeland Defenses ...... 134 Line of Communication (Logistical Support) During ;.".... 'Third Phase .. *...... ,.«. 135

.."-HAP'TE~R 711 "Fourth Phase of the War (July - December 194)4)

Operations S npary.for, ~ourt4 Pha-s' ...... "...... ,.137

Development and Preparations for "Sho" Operations .:.."... 138

Preliminary Actions Leading to No 1 "Shot' Operation «...., 146

Start .and Ponduct of No 1 "Shot' Operation . " ...... ~ 149

Operational Conduct in Other Areas ...... :...... 154 P'~ . f' Army-.Navy Discussions Regarding Unified Air Forces' .,.2"C'or~mh'd **S* *b*b9S*,@9*[email protected] 162

Measures to Facilitat9 Railway Transportation on the

CHAPTER VIII w"- Fifth P-a f h r"(aur August 1945 ) PART I ------Operational Stage Prior to "Ketsu-.Go" (January- flarch l945) *.".".*.... ., .. *.."."."""". r . ... '.,.. 166

Situation Review and Conclusions Regarding US Strategy ". ,. 166

"Attitude f Russia" and Military Preparations of. Ohungking .ainls " "","s",""""""""".. 7

Appraisal of Japan's Man and Materiel "Power ... ',...... :.. 170

Fundamental. Strategy of Impe rial General Headquarters .... , 172

. "" b1b~wihmt o Civil Defense Plan .. «. " "...... :.:..... 176

" r "artionI'Ary obiization Schedule . " ".""",sa". "...I ".*. -78

Central Pacific:, Formosa and Nansci Islands' D sections ~... ~~ ax~I' Orations ...... " ...c C.*C" ... . ,....;..e* ;:....*.. 185

* Prepa'ati'onsamnd Disposition of 'Forces in Korea,China

and Manchuria - *ce .'& C "".Ol0. ."". 188

Lir~e of Con munication. (.Logistical -Su'pport)' During thi~s Period * *...... ~*...."...... "c..." .0. 191

iv. Co n d uO c t e ro f t . 1Ar Ho m se l a nL d Onp e rm a t i oo nb s an n d fS, t t r ae t eH g ym l n"...... "... . . 1 99 3

PART IIT- "Ketsu-Go"f Operational Stage (Atprii .- August 1.9115') . "...... "...... 205 JOerationaI Preparations Resulting from Stnation.

Estimate ." g"**g...... wg9*gg"...... g. "...*g.*C 205

*Objectives **....$.9*. 41.*...... 1.... 0*.0. 209 Tin of Communication (Logistical Support) Preparations.. 211

Transportation Preparations *g"gese"«s"I.ego"eggeegggggsg 212

Communicatiobn System Preparation .. ,...... "...... "... 21)4

Land Forces C'oicentrat-ion Plan ,...... ,...... 215

. , , yavy Strategic Collaboration "...... ,...... 216

General Military Preparations and Disposition of Fighting Forces .. " . , " .... , ...... * .g.. .*" :;..217..

Direction of operations in Korea Urea ...... , . "...o. 219

Direction of Operations 1!gaiinst Teny Invasion of Okinawa 221

Main iCo e'aIOperationsit "...... 225

China Operations During the Okinawa Campaign "...... 229

Nannohuria. Operational .Preparations ..-,"...... 231

Summary of 03e ations Jun~e19)45 to ind of War ...... 235

Homeland Ope rations ... .. *..."..".*.... S..r...... 236

"Air per t ::#" ~ . .~... 37

*Operations After Fall of Okinawa a.., ,...... ,...... 2)42

Continental Organization Revisions and Operations s... 24)4

Operation~l1jconduct Following Soviet Entry in War ..." 2)47

South Burma and Philippines Operations .. . g.,g .. g 249

Line of Communication (Logistical Support) During: Fifth Phase ""e...... g..."ge.. g~g.~..q 24 Teiafiotif'6Vostiitie s ...... 251

Chart 1 1 ouar Ifembers' of'.the' Liaison. Conference July 1941.--August 19)45 .... «...... ".... ".... 9 Chart 2-- The Disposition -of the : Army:' Land Units 1 .(D-,e,Vei 1194 ':V . ,"'sNw0'er""g" j fge ""g t(*y """ . e r"o g- .. 1)4

*Chart 3 -- The Disposition of -the rmy. Operatioqnal; Supplies (Dedember 94)~eggge .g* ggg OC ) Chat'4'-;,'The Disposition of the irmy Air Units (December 19hi1) ..... * * .. .. *e 14li

Chart" 5 -- stimated Army Strength of the -enemy "in.the :south

(September 194~1) .... «. " . 6.6 0. " "," " "09", " .as 22

Chart 6 M-" stimated Enemy Air Forces in the South,

Chart 7 Estimated 4nerny Naval E or ce s Operating t o .the,.

Clhrt 8 Estimate of the Enemy Strength, May 194i2 . " . .... 48

C1t 9 ' tat& 'of Posdbe increases in Fighting Power of US-British Forces (May l942) ." "...... ".. 8

Chart 10 - "Shot: Operations Air Strength " ...... ,.. ;.... 12 Chart 11 Plan of BJmployment of, War Materiel Re imported

Chart 12 S ource of Army Air Force Operational Strength. in r. ., .. Caise' bf Tnem tacks. * . Planned tiransfer and Allocation of Army Planes A 2nft Nansei Islands or Formosa *..:....a...«. 200

Chart "13 - Planrned Operations and Strength for Army Air Force (Homeland and China) *...... S. " ... 200

Chart' 14 - Source of' Navy Air Force Operational Strength in Case of Enemy Attacks Planned Transfer and Allocation of. Navy. Planes 'Aginst"Mansei Islands, Formosa or Iwo-Ogasawara Islands ".".,""""""fa9.e.9.e*.aaag.aa.9".as.. e 200

Chart 15 -'Planned Operations and Strength. for Navy Air Fo rcesl(Homel nd, Southwestern Pacific Area and turface JEscort **ee a .a* ** aee.ea ae9 *e.,e"e.. * 200

Chart 16.« Casualties and Damages Suffered from Air Attacks

Chart 17 ..Revised System of High Command ...... , .. 207 Chart 1:8 Plan of the ,Army cleneral Staff -regarding the Maneuver of Land Forces in .Ketsu-Go" Operation 215

Chart 19 - Strength of Army. Air Force En fMy 94)... 225

Chart 20 Dis~pdsit'ion araT 'Jti'lination "Pliti "of the Air ... "9""""099. Gneral Army " " ,aae...... "...... 21

Char't 21 Disposition and Utilization Plan for the Navy

Air Force. "".!"":"s"_""""""."..a.99.b.9 .. a,&..«""... "2141

SuppLJ {2ITT I ,-- Ch no1Qgy of. Major Events. during Gre .t E~ast Asia Wr"...... ?.. . 1"4006*,..t

SUP2'Ii NBNEPT II,*- Chronology of Major Iiaio.Porferencos. during' Greater Eat AsLa War "".*."+,* .,0" 041""":""5

vi SUPP i I'iTNT III -- Chronology of' Major Actions & Decisions by the Armay General~***Oae~s**7 Staff :......

SUPPLIV NT IV -- Guide to Designation of Units,. and. Their P ur po se san asze......

vii CHIPTEE EI',

JapanesesNilitary %Command. Organization

'State Affairs ,ard 'ttupreeme Command" Relationsh

Based upon the Constitution enacted in 1889, domestic and foreign affairs (Civil) in the Japanese Government were executed, generally, by the Emperor with the assistance of appropriate State

Ministers. Responsibility for results remained with the respective ministers and did not reflect upon the Emperor.1

The Anr General Staff regulations and the Navy General Staff

regulations, developed to implement Constitutional Clause No 129 provided for execution of and responsibility for operational re-

quirements necessitated in support and protection of the Emrperor

as' Supreme Commander. To advise the Emperor in his position as

Supreme Commander, the necessary assistants had been created for

command responsibility to the throne in 1878 by creating the posi-

tions, Chief of Jrmy General Staff and Chief of Navy General Staff.

Their duties and responsibilities were clarified in the General

Staff Reguations of 1889. As Chiefs of the respective branches

for Army and Navy, these were the working "Supreme Command' authori-

ties.

The State Ministers for Domestic and Foreign Affairs had no

connection with the "Supreme Command" as Constitution Clause No 31

indicates. The only exception to this was in Concurrent Affairs which is explained later.

Even in war-time, the separate responsibilities to the throne were still hold by the respective Chiefs of Staff for their specific branch of service. Though an Imperial General Headquarters was

1 Constitutional Clause No 55 - The State Ministers assist the Emperor and are responsible for the results.

No 3 - The Emperor is sacred and in- violabe.

2 -Constitutional Clause No 11 - The Emperor has the Supreme Command of the Army and Navy created, it-did not break,the:. basic responsibility. However, in

cases of problems requiring joint action, Central Agreements ar-

rived at by the two chiefs of staff were handled through the off ice

of Imperial General Headquarters. It is important to emphasize that by far the major number of directives and orders issued by

Imperial General Headquarters we:e not of the Central Agreement type.*In fact, they were mostly individual m'ry Section or Navy

Section-actions covering their individual fields of responsibility to the throne.

The Emperor's .non-responsibility clearly defined' that the

Emperor was not responsible for the entire sovereignty of the nation. This not only applied to'thle domestic and :foreign affairs but also to the "Supreme Comnind"I* Highest responsibility of the

"Supreme Command" was to organize, supervise and represent in direct access to the throne the Army and Navy General Staffs..

The Army field comm anders, though directly responsible to the Emperor, could n:)t report directly to the throne but, presented their recommendations through the Chief of Army General 'taff who was Chief of the Military Assistance. Agency to the Emperor.

The Constitution enacted on'1 February 1899 and the Army

General Staff Regulations enacted on 7 March 1889 were based in genera1 upon Prussian laws,

In general, the 'laws, Imperial decrees, and other Imperial proclamations had to 'be endorsed by' the State Ministers. This had the effect of binding their responsibility and relieving the Em- peror. 't Suprene Command" Independence and Direct Appeal to the Throne

As.. mnt icned -befor^e, the, responsibility of the "Supreme Command"

was entirely outsido .of the State inisters administrative power wihich included the War and Navy .Ministers. In other words, the

Chief of Army Geieral Staff or tie thef of Navy General Staff as-.

sisted the Empcror on matters concerning strategy and operations

and were privileged. to appeal..directly to the Emperor on such mat-

ters without dgoing through the channels of the cabinet or the

premier. This was called the independence of the "Supreme Command".

Similar authorized appeals made by te War or Navy Minister, Ue

Chief .. off the General Staff, the. Inspectorate General of Military

Training and sometimes by the Inspectorate neral of the Air Force

in connection with Concurrent !ffairs (which were overlapping responsibilities with the "Supreme Command" in a broad sense) were

customarily called the direct appeals to the throne. Thy; proce-

dure forthe direct appeal. to the throne was stated in the cabinet regulations. Reports to the Premier from the WUar or Navy Minister regarding such direct appeals were mandatory,3

"Supreme Command" and State Affairs Concurrent Matters

As for the correct methods of govertumont procedures, the afore- mentioned facts should not be difficult to understand, However, there wer°e matters of an ambiguous nature existing between the general State Affairs (domestic.and foreign affairs) and the "Sup- reme Command" which might be confusing.

.These were the Concurrent Affairs or the affairs of the

"Supreme Command" in a broad sense. These were joint responsibili ties in military affairs held by both the "Supreme Command" and the general Statc Affairs. The principle Concurrent Zffairs were

3 The Cabinet Regulations, Clause No 7 M Matters which are appealed to the Emperor concerning -Military Secret~ and orders mst be reported to the Premier from the War or Navy Minister, except those which are granted to the cabinet at the Emperor's discretion. the Army and'Navy organization .and the determination of its stand-

ing troop strengths'.

They also in6luded authoriy tneeded' to, construct and maintain miitary establishments such as military standards and, x:gulations,

disposition of units supply of materials.. etc.

Thus,.the relation between the State Affairs and "Supreme

Command" in Concurrent Affairs was a.n overlapping' one.to a degree.

The Concurrent Affairs concerning the Army were handled by the War Minister, Chief of t'he General staff, Inspectorate General

of Military Training,, and s rnet'ih s by the Jlnspe torate >General of the' Air Force accordin g to their authority 'and nature of the work.

The respective *.hief was.responsible either independently. or jointly with the, other chiefs,, The: War Minister' was responsible for the executi on of all matters. Regulations of each office expressed the authorityl of each chief in handling Concurrent Affairs., In addition to 'regulatie.ons, there was a mutual, agreement 'establishing areas of respons -fob ility for the War Ministry., General Staff Head- quarters, and the Inspectorate General ofMilitary -Training.

Matters which were to be handled by the Chief of General Staff involved the use of troops for 'mainaiining local public order; the dispatch, duty and relief,., of .'overseas expeditionary forces; war- time 'organizatiions; mobilization.plan; grand,maneuvers; etc.

The Inspectorate General of Military Training' ws responsible for establishing the military training regulations, the drill regulations and manuals for the various branches of service, etc.

The War Minister would handle matters conernnthe standards and design of weapons, finance, sanitation, veterinary and judicial affairs, etc. Also handled by the War Minister was the peace-time system concerning military training and. national defense, special inspection, etc. To clarify peace-time operations it is pointed

1f" Constitut ional Clause 1-TTo The peror 'decides the A'.rmy and Navy Organization and their standing troop strength. out that the Chief of the Army General Staff was responsibe for

drafting the organization of each unit,:8fces and schools under

his jurisdiction. The Inspectorate General was responsible for

schools under his jurisdiction. The War Minister was responsible

for other offices, schools, depots,.etc.

:Methods for Issuing Concurrent ffairs Orders

The' methods for issuing orders on Concurrent Affairs were in

accordan e with the Military Order ho 1 of 1907; thoy:were in forms

of Army or Navy announcements over the signature of the War. or Navy

Minister arid treated as Military Orders which the War or Navy Mini-

ster.,was responsible for executing. This system of Military Orders was developed to coves matters resulting from concurrent interests

of "Supreme Command" and State ,Jffairs, in items affecting the A.rmed

Forces,

The Military Order No 1 of :.1907 included,: . Ql.use No 1 -

Regulations concerningthe "Suproire Command" of the 'my and

Navy will be the Military Orders if they are sanctioned by the

Emperor; Clause No 2 - Military Orders which must be .publicly

announced will-be dated and countersig ed .by .the responsible

War or Navy Minister. They will be accompanied with an Tj2--

penal edict bearing the Imperil _gnatare and seal; Clause

No 3 -- The Military Orders are published in the of ficial.

gazette; and Clause No J . - The Military Orders are immediately

enforced if the date of enforcement, is not stated.

Principles in lssignm ent of Military Officers as War Minister

There wore two major measures for asystem in assigning officers as War Minister,' The War Minister acted as a member of the cabinet to carry out governmnt policies and also assistd the Emperor on important matters concerning military affairs which 'were not involved

'i state 'affairs. He had to possess : fficielt' qualifications and

...... experience to achieve his purpose H e was responsible for consolidating the civil and 'military affairs and achieving cooperation between the "Supreme Command" and State A'ffairs.

In order to concentrate its attention on its basic respons- ibiliti,.es, it was cdnsidered better if the firmed Forces were to remain out of politics,, generally. If a civilian official were assigned as War Minister who hadpeace-time power 'to *control Armed

Forces personnel and civilian omployees, the Armed Forces could be used. as a ,tool for political issues. Too, :irmed Forces personnel might enter political parties. This could cause poor relations between branches and reduce control and unity in the Arxnr and Navy#

The system of assigning a military officer as War Minister and a naval officer as Navy Minister evolved from a custom calling for the War and Navy inisters to be appointed from candidates usmitted by 'the Army and Navy. Usually, the branches rwereerequested to recommend a 'candidate for the posii.on; however, this was not a regulation. The branches did not coerce the candidate to accept the position- 'but left it up to the Premier and the officer re- c ommendied .

Imperial General He adquarters and Government Liaison Coferences

In November 1937, :Imperial General Headquarters was created to coordinate -n-..y and Navy operations 'resulting from the China Inci dents.Immediately after this, a Liaison Conference system between

Imperial General Headquarters and the government was-'developed to coordinate matters of joint imortance to the "Supreme Commnd" and domestic or foreign (civil) departments. Later, this conference had somemodification in its formation and methods. Although it was -called, variouslythe Round Table L aison Conference between the Imperial General Headquarters and the government, the Supreme

War Direction Conference,,etc, the conference principle was maintained continuously until the termination of the war with no changes in the fundamental objectives,

After the formation of the onoye Cabinet 1I, 22 July 1940, national and foreign policy decisions became increasingly ixalportaxx during the war. The conference acted as the Supreme War Command and was of major governmental importance. Additional references to the conference liaison system in the text are referred to as the

Conference.

Lgislative Characteristics .of the Conference

The Conference was established by mutual design and agreement between the goi rnment and the "Supreme Comiand", In contrast to this, the Cabinet Council.was provided for legislatively. in the

Constitution. Ihere decisions of the Cabinet Council were authorized by regulations providing for cab inet organization5 the Con ference had no such authorization, embers of the Conference wre jointly and individually responsible to see that decisions of the

Conference were executed properly by the government and the "Supreme

.Command".,

Decisions were formally executed through separate action by the "Supreme Command" and the government. The Premier would refer

S a matter to the cabinet council and the two Chiefs of taff would carry out decisions of the Confrence requiring action through

Imperial General Hadquarters 0 The relation between the two Chiefs

of Staff and the War and Navy Ministers has been mentioned, previous ly.

Th cabinet organiz ation Cl use o - The f oowing subjects must be referred to the cabinet council:

Legislative bills, budgets, and statement of accounts; Foreign treaties and important international stipulations; Imerial ordi- nances concerning.the enacting of government organizations, rules, and laws; supervision of disputes between the ministries; petit ions granted by' the Emperor or transferred from the Die t; extra expenditures; assignment and resignation of the prefectural governors and officials directly appointed.by th Emperor; and, important acmini- strative affairs in serious situations which are handled by the heads of each -ministry must be approved by the cabinet council Althoughthhe Conference, had ro le gislative authority arid its decisions were subject to mutuala:g-rereet,: :the matters which were decided upon received full respect from the "Supreme Command" and the Gbvernment. ConIsequentlythe Conference had thc highest authority to conduct war and played a significant role.

Relationship. Between the=Empror and. the Conference

'he State Ministers had full respon ibility for, state ffairs arid for such items acted .as adviser-to the .throne, The two Chiefs of Staff ' took full responsibility for "Supreme Command" matters and assisted the Emperor in their field. The Conferenc did not charzge this. alignment of responsibilities. They were clearly sepa- ratcd into the individual fields of State Affairs and the "Supreme

Commnand" They were.entirely different fromthe State 'Iinisterts joint responsibilities on Conurrent, A',ffairs decided upon at the; cabinet council.

One of the matters decided upon by members of the 'onference was. to make a formal report of iportant matters to the throne for approval , This report was made o er the joint signatures. of the

Premier and-the two Chiefs of 0taff (or all three of them reporting in person). However, the execution ofmatters decided remained as befog with the St 'tbAffairs' be in " handed by the. Premier and

tSupreme Covand" affairs being hand by the two Chj fs of Staff.

The idea for joint signatures was devrelopod $o. li ison purposes in reporting to the throne.

Conzrrice (Council) iri theImperial..Presence

This type opf meting meant a confebrennc in the presence of the

Emporor and not one presided ovrer by the Pmperor. This council was a deeting for discussing important national policies so that the pro- cedings could,be' heard bythe -mperor. The subjects decided uporn at this council still had to be passed through the legislative procedure, lit the end of the war, this council in the imperial presence remained unchanged in every respetj

Conference (Council) Agenda Example?

Important subjects concerning the State Aiffairs and the Suoreme

Command were taken vup in regular sequence as indicated by a typical agenda: important national.policie s . such .s the af idmental plan for conducting the war, etc; importen7t diplomatic measures; regulations concerning military operatidns and national power; and, the administration of occurpied territories, and the disposition of the

territories.

The people presert at council presentations included for the government:

The Premier, Foreign Minister, War Minister, and

Navy Minis ter; and, foi. the Supreme Commnand

The Chief of' rmy General. Staff and Chief' of Naval

General Staff

In addition, specified state ministers attended at certain times and other cabinot inijsters were callcl as needed. The Presi- dent of the Privy Council always attended this council if' the Em- peror were present.

6 At the termination of the war, the Emperor was reported to have made a personal decision at the council. This was. belicvod to be true by the general public. Actually,'it was expressed as a desire (according to government tradition) and made an effective decision through Council and Cabinet action.

An effective decision for terminating the war was so extremely delicate that it may have caused anarchy in the nation, As a result, the Premier could rnot giveo a decision from the council. He solicited the Emperor to express his opinion, The Emperor's' statement agreed with the Foreign Minister's opinion., After -the 'council, this subject was presented and decided again ate. cabinet council. It was solely because of the fact that the government and the Supreme Command could not: decide the grave matters for terminating the war that the Pre- mier solicited the .emperor for his opinion' The public also ackno-- ledged thisfact and agreed for the tenination of the war. This decision was an exception which would have been entirely impossible without the ;Emperor's power.

7 This Agenda for the Council was also the sequence used in order of business for the Conference. CHAPTER II

General' Situation Before the War

Military Preparations

Immediately after World War I, the Japanese Army was inferior

to those of other .world powers in size' and quality. However, when

the China Incident started following the Manchurian Incidents, Japan

maintained a sizable number of troops. The object of such military preparation was to provide the necessary strength for conducting and

quickly terminating the China Incident. At the same time, it was

considered necessary to secure sufficient strength for defense against

Russia.

From 1940 to the beginning of 1941, . Japan anticipated .success-

ft. diplomatic negotiations and did not undertake large-.scale war preparation even 'though she faced international problems with Britain and America, Immediately- after the outbreak bf the Russo-German

War in June 1941, Japan rapidly increased military preparations.

This was done as a preca-ftAion against a possible Soviet, ;attack resulting from the existenc of the Tripartite Al.lincae A t the end

of July l9l, merica, Britain and the .oth rlands broke of economic relations with Japan. In. SOptember 19:1, only three months before the outbreak of war, Japan felt forced to start war preparations to meet any emergency in case war with America and Britain became

inev'itable. During this period, Japan was following a national policy of dual 'tactic s (diplomatic no gotiations and war preparations) and could:not concentrate her entire effort to war preparation against these two powers War preparations for the Pacific, particularly against merica, Britain, and the Netherlands were minor.

The -initial military strength at the beginning of the war was gath. eBed by transferring a'part of the. generalNational Defense Power to the South. Later,.depending on the progress of war, the main strength could be gradually poured into the' South, Faced with these 04 I c3 I

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Chart :1~ conditions-, Japan had to 'rush into full mobilization to maintain her very existence.

n addition to armament,' war preparations included industry, commerce, finance, monetary exchange, diplomacy, communication, and measures for maintaining public order, public opinion, etc. This report will 'describe the 'war preparations'carried out by the Arny..

They were not originally planned for'the ''Pacific Campaign but later were. offvalue in that oper tian.

The ' results of the ino-Japane and Russo-Japanese -iars reduced the menace from China and Russia, and Jap.:n established some rights iii China"; At the -,same time, Japan increasbd her rights on tha Asia- tie Continenit gadually through e coniomic and political agreements,

Before the IManchuriariIncident, Japa~n s military preparations were etremely inferiorto other world. ie.rs .The peace-time strength was seventeen divisions hile the war-time strength was established as thirty divisions, In case of an emergency, it was extremely doubtful whether Japan could wage war against a single power.. Although, every effort was being made by the administration, it was not possibl to create sufficient armament to assure adequate national defense.

Tn 1931, upon the outbreak of the Manchurian Incident, Japan was 'forced by circumstances to carry out the fight.

The. great expansion of military preparations _by .,Russia and her pressure against Manchuria forced Japan to increase her military strength for national defense. Studies regarding this si tua tion were begun. The army General StaffC oncluded that Japan required sixty divisions in peace time end ninety to a hundred divi, sioiis in war time, 'but the economy could not support such an increase.

The government approved an army-sponsored, bill peeking an increase of six 'divisions in 1936 . During 1937 and 1938, the government a - proved an army plan to add~~lh ivisions ;by the end of 1933 Because of national conditions; especially ;financial, the government could

not have approved the full needs as a continuing project.. As a substitute the government was asked. for the nocassary expenditures

each fiscal year. "In this way,.the above increases' in. strength were. accomplished.

From 1938 to. 1941, the combat zone in China gradu~ally enlarged. Simultaneously, the neoessity for dofonse ,4gainst Russia was in--

creasing. To meet these factors, the, gadual build-pup, in forces jwas undertaken -each year. The, purpose .was ,to aehieve a rapid set- tiomont of the Chin~a Incident and to evelop security against Russia,. The increased strength of the divisions, the Avmy Air -Forces, and

.the, mobilization of :officers.and enlisted men -are shown in the

.folowing. table Nos. , , 2 and 3, (1.),Table Show-ing the Number. of Divisions. (From 1937to 91F

. Year T! I ._...... _. _ _ _ ...... _. 13 198 1939 1940 J1941 } Disposition- .

~Korea 1.2 71 1111

Macuia .58 , 9] 12 13

China 1.6 24 2 27 27

Total 1 214. 34 41, 0 5i

{Remarks*- 1. From 1937 to 19140, the number of division. is I.shown as of the end.,of each " espective year, } ~while in 19141, the 'total. as of early Novemnber is shown~. 2. In addition to thesdin. this table;, there was a

Cavalry Group. ,.

3.In 1937, there remained some margin, for. mobili ation,.=but from198&, nd;one thenumber' of * divisions conformed to the capacity to equip ~.* and train them,.; (2) Table of the Army Air Forces (From 1937 to 191)

a .I-UII----U-N---~----~~ ~----i------Year5 1937 1938 1939 19140. S1941 Cassificat t- ., It-- --- rulr~------I--- I 56----- 2a :Fighters

ILight Bombers 12 16 126 28 36 i

Heavy Bombers 9 17 19 22 27

t Reconnaissance 2 1 lanes 12 13 18 20 32

1/Total 5470 91 106 1

Remarks:r 1. The figues in this table present the number of squadrons at the end of March of each year. The figures of 191.1, however, show the number of squadrons as of early Iovemberr

2. Although the number of squadrons increased, about a year was required before the new ly organized unit could reach actual combat strength.

(3) Table Showing the Army Conscription (FromL9336 to 1941)

Year 1936 1937 1938 1939 19140 191.1

Personnel 170 170 320 340 320 330 (1,s000) 1 .

v0n w ith th is increasin g ! y strenrrm g th, it was im possib tolle

give a decisive blow against the enemy in China. At the same time,

the Army could maintain only one third the Soviet Army's fighting

power, along the Manchurian border. Thus, the anxiety over net .onal

defense could never be eliminated. This increase in the Army became

a factor in the Pacific War preparation, but the main objectives

were for the China Incident and Manchurian Defense. With the outbreak of the war in 1941 l, a part of these forces was sacrificed by being transferred rapidly to the south to cope with the new situation,

In December 191, the total strength of the Army consisted of

51 divisions (excluding one cavalry group), and 59 brigade size units.of various types as the main land units, and. approximately

forty air-regiments. The disposition of troops and the operation,

al supplies were as shown in Charts 2, 3 and 4.

Training Programs

The important manuals and regulations such as the "Military

Training Regulations"., "Field Operations Service Regulation!, "Bat.

tle Principle", and others of the various branches which had been

the training standards for a long time were taken from World War

I references. .A special training plan was established for the national forces which would develop the best potential of the soldiers. As part of this training program, attention was centered

on: recommendation of mobile combat tactics; adoption of an en-

circling annihilating attack; substantial ±mriiprovrme.' nt of coordinated

operations by all branches of service; the importance of, close

combat; the consistent encouragement of night attacks; training

for self-decision by all officers and men; and, emphasis on train-

ing of the two-year soldier (two years being considered the too

necessary to develop a qualified soldier),

Before the Manchurian Incident, there was no idea as to who

the enemy might be and training was conducted strictly according to

the manuals.

After the Manchurian Incident, the training emphasized possible

tactics for use in Manchuria against Russia. Eiven after the China

Incident in July 1937, the training emphasis remained unchanged.

Field Operation Service Regulatons prepared in 1939 were developed

as the result of the possible operations against Russia. The Disposition of the Army Land. Units (December 19141)

Naeof.Eq Location Divisions Mie Area______Brig Gen Defense Cmd Tokyo 0 (a)

F stern Dis Tokyo 52d 1

Hoead Central Dist Osak 53d, 54th 3

Korea Western Dst uos3

Formosa Northern Dist Sapporo 7th 1

Korea Army Eq Seoul 19th, 20th

Formosa Army Acq Taihokui

Kentung Army Eq Changchun 10th, 28th, 29th 1

3d. Army Eq M'*tauchiang 9th, 12th 4

14th Armay ]k Peian 1st, 14th, 57th 5 Manchuria 5th Army Eq~ngan 11th, 24th 4

6th Army Eq Tlun 23d 1

20th Army Eq Chihsi 8th, 25th 4 Kwantung Defense Caghn5 ___ Cmd_ _ _ China Exped tnkn Azi Gen E ______A~rhCiaAe PeipDing 27th, 35th, 110 5

lst Army Eq Yangci 36th, 37th, 41st 3

12th Army Eq Licheng '17th, 32d 3 China Mongolia Garrison 2thCaG, 1

11thEq Amy d, 6th, 13th, 2 ______4th, 39th, 40th___ 13th ArmyEq Sbanci , 15th, 5 ______22d. 116th 23d Army Eq Canton 38th, 51st, 14th 1 Southern Army Saigon 2lst(b)24) Eq (Ge)______4) 14th Army Eq Takao 16th, 19th 1 The South 15th Army Eq FrenchInoCia 3db,5t

16th Army Eq Takeo 2d 1

25th Army Eq 5anyGuawrd, th, ______18th, 56th(b) Remarks: a. In ditIon, 10 Depot divisions were in the Homel1and. b. Actual dates for transfer of comnd were departure dates from previous stations: 21st from Chingtao (20m Jan 42); 334 f rom Naking (13 Dec 41); and 56th Directlyf oeadc. attached to the Imp Eqa, 4th Div (Shanghai).

d. Directly attached to the Imp Eqs, South Sea Det (Bonin Is).

Chart 2 Thu Dispostion of the .P_r ny Qp r..ata ona1 Suppli :s

(Duc.rabur 1941l)

Disposition of Durn7s Unit I Total L.."" .. FSupplies. Quantity Quantity Hoo- .. +-_-land South North China quantity used by 10 E..17 48 30 adi-vi s-oion ,Std'. lQ105 (14) (6) (8) Amrmunition campaign)...... }.. ~..

Motor Car 1,000 cars parx'h Fuel month 3-15 (10) 140 50 Il25 h2

Avxiation _ 77 (Ai .U lFuel& :isAirOn Brig .to) 5 12 45 1 Ammunition nor month 165 (Fuel) 88 20 507, 0nDiv Rations per month 370 (341) 86 98103 8

; The figures shown in parenthesis represent supplie spro- 1 k Remarxk duced durin' Decemuber, and are~ included in the figures at .out the parenthesis. This table includes the shift in supplies described in the 'next chart. i.

Chart 3 .' i f T. I I IQ

C H I H

'ii d OixC Dq VI-C-4 CV 4 irk uI ----

--- . -----. ----- t---- i -- +------i--

HC' '--A"!

iii I ~i I ~JH

P ~FH~ I j

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H E

0C)

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cll, ri

Chart' b In:both incidents, the madin force of the Japanese National

Army engaged inferior enemies with poor equipment., Success caused

relaxation of the training standards,,,

Following the Japanese Armay expriences -against Russia in the

battles of the Changkufeng in, 1938 and ,Nomorhan incidents in'1939,

training emphasized systematic, scientific . fightin g/ techniques and realistic combat training. China Incidents continued and drastically

increased the operational strength. requiranents of the Japanese

National Forcesb : To meet this need, Japan mobilized the officers

and soldiers of all ranks from the first and second reserves . With this epansion, training standards declined further and the vale: able high standards of. a picked-Army were a thing of the past.

.Traininug the Army. received before the Pacific War ~was inadequate . Most of Japan's new actions would:rquire landing- opera- tions because of. Japn's geographic location. However., the train-

ing was given only to spet4 ije divisions, Praviously, the neces-

sity for a blockade against China ini 1940 and 1941 had spurred

some training in landing operations,

In early 194i, the international situation was appraised by

the Army General Staff and revisions were d eveloped in battle training plans to include 'countermeasures not only against Russia, but

against American and F.itish fighting methods. A collection of

data and investigation' of fighting mt ods was mac, but time prevented gaining the results desired. The enlarged tactical

training program was started in June 193.1 for specific unfits in

Formosa, South.China and French Indo-China. Some reference books

'such as the "Characteristics of the Operations in the Torrid Zones",

"Common Sense of the American and British Forces", "Simplifice

Southern Operations", etc~ were compiled to help in training orion-, tation ,~ However, the material was very poor and could not be used for training manuals. Because of the China Incident, it was difficult -to provide this additional training for the troops located there,

Subscquent to the China- Incident,; fild; exrercises such as the

Grand Maneuver, General Officers' Mfaneuver, Staff .Officer's 'Maneu- vers, etc, had been suspended. The study and training of higher strategy and tactics were generally insufficient and the :trainin g to meet the American and' British Forceswas unsatisfactory.-

For several years, there had 1 been discussions and investigations concerning the type 6f air force tactics: to be used. There was a method of annihilating attack (similar t UtS strategic tactics). by the concetrated use of the; air force against major target or a mthod 'of directly supporting the land force, *The fomer prim- cippr was decided upon in t1939 and 190.O Intense training was carried out z'esulting in great achievrements during the initial operations of the Pacific War.

Expansion of National Defense Industries and War Materiel

Japanese armament before the Ma1nnchurian Incident was approximately twenty years behind these of other world powers. In 1936, ways were studied for modernizing Japan's military power. Hojocver, years of negligence in developing nowi weapons and aiiament greatly hampered an incre-sc in munitions factories, The basic national defense production capacity was very weak having been based previously upon small industries,

The Army prepared a budget and established a Five Year Plan for the munitions industries in the spring of 1937. Need for expansion of the basic industrial facilitie s to support a munitions increase was apparent to the Army. However, the legislature did not develop a bill to answer requests for such legislation. -As a result, the army drafted a recommended Five Year Plan for basic industries and submitted it for consideration, As such, it was not accepted. Points were included, however, in the !a.tiorial

16 :obilization Laws of 19380 '..These projects received special em-

pha'sis due to the rapidly increasing powers of the adjacent countrie.s.

Demands of the China Incident in-' July--August 1937 suddenly changed

the conditions, bringing the weakness of our natiofial defense in-

dustries to light. A 'national mobilization of munitions industries

was essential. They here placed under military control with the

approval of the Diet on 5 September 1937.

From then on, the peace time production methods which wore

being used to carry out the Five Year Plan for the'munitions in-

dustries were abandoned. With new war time methods and. military

control, production was to be accelerated.

The: original mobilization pogram for the munitions industries was limited to six months. Because the China Incident pdrsisted,

it was renewed each fiscal yearfWith the enactment of the Nationd..

Mobilization Laws, 24 March 1938, the necessary economic control

regulations were gradually developed to 'provide authority to execute

actions necessary to fulfill most objectives of the gbals incorpo-

rated in thou Army Five Year Plan drafto

The "Five Year Plan" for the ,tsic industries was carried out

immediately in.Manchuria .but. the start of the plan in.Japan was retarded by 'the China Inciderit which cut off soeie sources of natural

resources. As a result, it became a Four Year Plan beginning in

1938 with _the first year spent merely in planning, In addition,

the quotas listed in the plan had to be reduced severaltimes,

thereby causing remarkable slow down in its Qorall results.

Aviation, munition and parts manufacturing industries were

greatly expanded under this plan. The special steel manufacturing industry achieved a remarkable success, The machine tool industry

surpassed it.'s .goal, And, the light metal industry made. rapid progress. How&ovr, every other 'basic industry was far from its goal.

The synthetic oil industry and the development of hydro-lcctric power suffered particularly from the.lack., of materials.In order

to fill the void caused by thq synthetic oil industry being unpro-

ductive,, an attempt was made to import synthetic oil production

facilities from Germany through a rade agreerment.. The outbreak

of war in Europe in September 1939 caused, this to fail,

Efforts were made .to stockpile oil through a trade agreement with the Nietherland 2ast Indies; but negotiations failed here, too,

causing .a. critical point in the defense structure. The Second

Konoye and, Tojo Cabinets both tried in vain to overcome the weak-#

Hess of Japan's oil industry but were unsuccessful due to lack of

materials, experienced technicians and Industril power.. This was

.also influenced by the heavy demands for the manufacture of mui-

tions.

Finally, near the end of 190, the munitions industries were

capable, of producing replacements for battle losses as well as the

mobilization, needs, Just before- the iacific War, the following

production. capacity was possible:

Yearly Production Capacity Schedule

Classification L91L. iscal Yar 19h2 Fiscal Yar19h3 Fiscal Year

Army 'Planesp (quantity) Approx 3,500 Approx 5,300 11

Tanks A(quanity)Approx 1,200 Approx 1,,500 Approx 1,800

Ground Ammuni. Lion. '(quantity

used by a divi- h13 battles 50 battles . 50 battles' sion in std campaign) Bomfbs(monthly need of one 22 onths 80 months 80 months air brigade The distributing of ammunition and aviation fuel, the percen- tage'and the transfers made at the outbreak of war in 1941 were as follows;

Nachaur a t 27% Hoeland if 3 .1The"ISuth

1g51Ammunition I China

erial INavigation Fuel lChinW

Transfers made in Juy 1941 to meet -. the req ureirents in azchuria after the usso-German War. Note Transfers made '1imediately before the ~ War in i9!;.

Reserve a: rmy $2ul~ply St ockp .le Pre- as at ns

The ra materials for weapons, ammunition, clothing, etc were accumulated satisfactorily but no attelalpt had been made to stockpile petroleum product's before the China Incident.. In 1936, who n the military armament build-up was planned, only-200,000 Koku (less than 4o00 kilol:iters) of aviation fuel was allocated for stockpile reserves during the net few years. Anticipating a sudden change in trade conditions after the Cina Incident due to possible complications in foreign relations, necessary crude oil for manufatur'ing a proximatelytl50,,000 kiloliters of aviation fuel was immediately imported from America in the fall of 1937 to carry out the Chinese Operation for a period of one year. This was the turnip; pint of ourArmy policy for mobilization of suply reserves. This procedure was repeated several tames. The last such shipfnent was in the spring of 191x.. Similar measur~es were taken to re - plenish other important supply reserves (tool machines, tungsten~, nickel, etc) which- had become deploted. Faced with threatening world conditions' in l9h0, the Briny' deinand~d from each government. department strict maint enanoc of necessary'suppl~ies. Approximiately a three-year supply, or a two- year supply at least, for national consumption had to be imported. Munitions hold a high priority because' of the unreliable foreign trade conditions. The necessary imports were. arranged as a .mothsd to meet the crisis of a national shortage. This was called the mobilization of emergency supplies.

The oil' stock as of the end of March 1941 was as follows&,

Estimated amount including the Army and Wavy Appro~ 1,170,000 kiloliters Avia~tion gasoline

1? .830,000 Ordiriary gasoline

U 320,000. H Kerosene

U 320,000 Light Oil

" ,hi30,ooo0 Heavy (crude) oil 360,000 . t Machine Oil

The Army and Navy .oil requirements for the fiscal year of 1911, mainly for the China Incident were as follows:o

Approx 150-7000 kiloliters .Aviation gasoline-

ut 80, ttlf Ordinary gasoline

ii 103000 II Kerosene

,gi 4, oQo Light Oil

x ,030,-000 t Crude Oil

150 000Q Machine Oil Pt the time- (end of July 19141) of the American, British, and. Dutch' embargo 6n oil, it was .estimated that a: stock of approximately

85,0.10 kiloliters of aviationl gasoline anl approximately 2,350, 000 kiloliters of c rude oil would. be :available for a.se s other than filling

20 requirements of an additional two ye ars involving operations fol

the China Incident'. ,This amount of oil stock would not allow the

Army and Navy air forces to operate with their full strength for

over twelve months, The Navy surface forces would beable to handle a delaying operation for one year, but in case of contin-

uous decisive battles, only six months at most. CHAPTER III

Pacific War Operational Preparations

The China Incident became more involved. during 1938 and 1939

and Japan could not attempt a short decisive action because of the

personnel required and shortage of equIpment~Instead, Japan was

forced into unending battles. Twenty-five divisions were used for

combat, occupation of major cities, and, protection of supply lines.

In eastern "Russia, around the outer border of Manchuria, the

Soviet " romy had 20 sniper divisions and not less than 1,000 plans.

In contrast, the Japanese wantung Army had a defense of only six

to eight divisions, approximately 3o400oo planes and 300 tanks.

With the limited arms and materials: available Japan was not

capable of any sustained enga emnt against a third power. In

spite of this,'from 1940 on, the constantly changing world condi"

tions forced Japan to prepare for such a possibilitya

In the sumer of 1911 plans being carr id out-wore concerned mainly with the Russo-German War.. Secondly, th y'concerned the

American, British and the NetherlandvT economic blockade against

Japan in the summer and autumn of the same year0

Pepa rations Related to Outbreak of Russo.-Garman War

The'uropean ar which broke Qut between Russi a and Germany on

22 June l9 1 was an .important factor as a cause of World War TI,

The difficulties of inte;rna tional dipjlomacy caused by conflicting relationships held by Japan with bath'tie Soviets and Ger ai and

Italy indicated a potential criical emrgency. The Army General

Staff evaluated the development from every angle 'especially a possible Russian invasion of ' 4Aa nchuria. In order to prepare for

defenseof "Manchuria in case of Soviet invasion; troops there were

reinforced immediately. As of June 19 1, the Kwantung Army was composed of the 1st

Division, the 8th-through l2th Divisions, the 1.th Division, the 23d through 25th Divisions, the 28th Division and the 29th Division.

There was a total of twelve: divisions plus the 1st and 2d Taonly

Brigades and 2d and. 5th Air Groups Most of the ground units were incorporated into the 3d through 6th Armiec and th air groups into an Air Corps with both being placed under the command of the

Kwantung Army commander, The 10th, 28th and 29th Divisions were assigned directly to the Kwantung Army. Its commander was hold responsible for the defense of Manchuria.

In the beginning of July, the Army General Staff decided to increase the strength of the '\wantung ',rmy by fall the smme year,

The Army General Staff called this reinforcement the "100th Pro. p ration's while the Kwantung Army called it the "Special aneuver of the Kwantung Armyt.

The Kwantung Defense command was established with five independent garrisons as organic units, ach division would be reinforced to be overstrength. The 51st and 57th Divisions would be added (these were previously Depot Divisionrs under thy.,mobilization).

Air strength would be increasedo All line outfits attached directly to the army such as the field heavy artillery. regiments and ba)t- talions, antiircraft battalions and companies, independent anti- tank battalion, automatic cannon companies, inidependent engineer regiilents, signal units, railway units, etc would be increased.

Support organizations such as the motor transport uMits, transport companieos (draft and pack horse), service units., and the medical and veterinary units would b; reinforced,

As a result, tho strength of the Kwantung Army would be fourteen divisions plus units directly assigned to. the Army. They totalled a'roximnately 700,000 men, 11.O,000 horses: and600 planes. However, in comparison with the Far 2pastern Soviet Army of about twenty divisions, 1,300 tanks .and 1,.50 planes our defense force was still

inadequate. In September., some strength was taken ;from. the Kwantumng

Army as the war situation in the South Pacific began developing.

/ At the same time, the army in Korea was enlarged by over-

strength personnel assignments to the 19th Division.and some auxi-

liary units'. Some dfensive and signal units of the Northern Army were strengthened, too.

Preparations Related to 1 conomic Blockade by US, Great Britain and the Nethc:rlands

The 1 usso,-German War and the movemeont of our troops on.28 July

1941 into J'Yrench Indo-China caused a break, tomorarily,, in the

American-Japanese negotiations 0 On 26 July, America and Britain, and on 28 July, the Netherlands froze all Japaneso funds in their

countries to retaliate against the Japanese invasion of rench

Indo"Chinaq. This stopped all trade relations with these countries and had a serious effect on Japan's existence. In'the beginning'of

Septembcr, the government and the Imperial Headquartrs had a solemn discussion on national policy at a Liaison Conf::rence,

They decided upon a policy of carrying on diplomatic negotiations with America and ritain so as to improve the situation. At the

same time economic self-sufficiency and defense would be boosted,

It was 'also decided to complete military preparations by the end of October under resolution not to refrain from war with the United

States, Britain and the Netherlands, in case the planned negoti-

ations failed. The prospect of war was not to be avoided if it were necessary to accomplish the self-xstnce nd self-defense

of Japan, The defensive preparations made immediately after the

outbreak of the RussQ"Germ an W .rwere centered in Manchuria but were gradually shifted to the South. The military preparations were performed concurrently with the diplomatic negotiation. In

case the'negotiation succeeded, the military preparation was to

24. have been declared a maneuver.: It was hoped the preparations

would end as-a maneuver.

Pre-%War Estimate of 'EnemySituation

In September 19l, Imperial General Headquarters made an

estimate of the strength and location of limerican, ritish, and

Ie therLand Armies in the outhe rn Territories as shown on 0 ha-r-)ts

5, 6 and 7. The total Army strength of the enemy in the mouth was :approximately 380,000 troops and 700 planes. Ths was rapidly

increased by the end of the year.

Since the Southern Operational area was under colonial control

of America, Britain and the Netherlands, it was estidmated to have

been undesirable for th m to create consolidated fighting power and

spiritual coordination between the white people. and the nativeso

Although the enemy air forces in Siam and burma were inferior

in strength, the enemy was believed to be capable of attaclimg

our landings with bombers and torpedo bombers from 1 aiay tudor cover

of the newly arrived "lSpitfires". The Netherland Air Forces might

support the British Air Forces from Sumatra and Borneo. The enemy

air force in the Philippines was considered inferior having many

obsolete planes except a few bombers.

Because of the threatening situation on the European Front, it was believed that the Far Eastern Soviet Army was transferring some

of her strength there,, Her strength in the Far astern Territory,

estimated at approximately twenty divisions, 1,300 tanks and 1,500 planes, was declining. If the Southern Operation were carried out,

united action by America, Britain and Russia was considered certain.

It was also anticipated that with the progress of the European War,

Russia might begin offensive action against Janpan, or America igiht

advance her Army (especially her Air orce) to the Far ! astorn

Soviet Territory. lEstima ted Army Strength of the xy in the South (September 19+1)

caion uitQatiis Number of ePer- Total. UntT~itte Units sonnet Personnel British British 7 ifb as 1,0 troops the nucleu~s

Indian Partly British 30,00 Stroops I jority Inisasto 6o,,ooo slat a lto One div 2 0 troops Mustralians the nucleusas 2t'00L 0

Malayan Partly British troops Mjority'Mlaak

insufficietly Volunteers trained, and 20,000) 20,000 ______equipped______British British 2,000 troops ______Indian The main staff 1 inf 'brig as 760W 35.000 troops are British the nucleus pu r Burma. na- Poor qual ity 26 inf bus as 2,0 Chinese tive trop s ______the nucleus 2,0 troops Chinese 7

Regular mainly consist of 1 0 British- a Indian troops 1,000 Borneo3,0 Volunteers 2,500 Regular 1,0 Hongkcong ~19,000 Volunteers 5,500 Regular hlif Americans per,00

army Haelf Nationls ______Philip- pines urnes americans 900 162,00 INti a1 Cie-Nationals 120,000 ______fence n ______Mwines 300

ete- Inner Terri- Partly 2 divrs as ,ax_ 0,0

__ndies__torytroops ~ronean15i bs 290 223,000 Regular to Total23,0 Total 27200

Strength ______352,000

Remarks : 1. In addition, there were apiprximately 500,000 troops in India, 350,000 in Australia, and 100,000 in New Zealand. 2. In addition the Pe~ulars of Siam wore believed to total about 30,000. 3. The total personnel of the Regular Army included the f ollowing troops: Regular Armies in Malay, British Borneo, Bongicong and the Philippines: .11 of the troops in idris and the Netherland-Indies, Y.rines in Guam and the Philippines.

Chart 5 Estimated Enemy Afir Forces in the Soath

(September l9.41

-D - ______- Numfber of 7uber of Total 9quadrons Planes Planes JTerri- N L irplane s 2 Bomnber s 4 48 Fighters T Reconnaissance -~-'~~-tover Malay ~ 200

Seaplanes 3 18

Torpedo Bombers 2 I 2 . .. _ _ . B om b e r s1 i

Burma Fig.hters and Bombersj 1 Approx Pursuit planes 2 i 50ro Volunteer army l1 Hongkong Training planes 10 -i Bomber s1 suit plane s 3 tPur } ver , Philippines reconnaissance 18 160 planes1 Sea Patrol Bombers 2 30 planes Carrier planes' 30 Bombers

300 Planes IFtg hters 130 Netherland I Indies Reeonnaissanice, Mpane - 36

Sea planes 120

Total I !pro S1. bIn additionorx20pae to this chart,nIda there5 werenAsrla believed to and 100 in New Zealand, Remarks 2.:. In addition, aoaprox 180 planes were believed to be i.n S9iam.

Chat '6 .nernstln~ted thevaSForte Sepotember 19.1)

Battle i..Airozraf I, to u-fte Country Location ships carr_er'dSTcc aie China & Philip- sines area iongkong 3 14. _ Sinpapore2 S6 214 Colombo area t9 { 2 I13

B3ombay Area

__ i. ' Eastern Africa i Britain Aden & .ed Sea Area S 2 3

Australia. are-a i_ 19 N~ew Zealand

area __ i - 1,....:.: .. E'ast 02 Hawaii 1 1 i Mfediterranean. Sea t1 20 2 ------China. & Philip- America nines area 14 2 1)4 17 :26 Hawaii area 18 16 28 143

-- ...... ------Nether- Tether annc land Indies 0 19 .56

Chart 7 On. the day. the To jo Cabinet came into power, studies were

inaugurated in the Liaison Conference. regarding international con-

ditions and in particular regarding objectives, methods and pos* sibilities of;success in waging war against the United States, Great

Britain, ,Holland, and China, simultaneously.

As the result of the above study, on 15. November 19.1,a deci-

sion was made regarding the objectives and, principles to follow in

bringing such a -possible war. plan to successful conclusion, This decision was'entitled,. "Plan for Expediting the Termination of War

.against the United. States.,- Great Britain, Holland ad 'the Chiang

.ai shek .g.ine". Its main points were as follows:

1. 3Yy cyig out a spoedy armed of ensive,, Japan will

capture American, British and Dutch bases 'in East Asia and

the .Southwest Pacific area and establish a stratbgically

superior position

2. By firmly se curing the. southern vital resources areas

and the main lines.of c onun ications, Japan will establish a

structure that will be self-sufficietint- feo an extended period

of time.

3. Everyeffort ''will be made to dra wout th, mn strength

of the American Navy at an appropriate time; seek a 'decisive

.'battle, and , de stroy it.

. Japan, Ger-many and Italy will, coop rat. and, make

effort to subjugate England first. For this purpse, Japan

will endeavor to sever lines' of communications bwetzxien England,

Australia, and India by employing political strategy and.

destroying comrmerce, and cause the latter two countries to

revolt against the former.. At th same time, Japan will pro-

mote-the independence of Burma and, by utilizing this result,

.instigate.an independence movment in India., .or the sub juga"

tion of Great Britain, Germany and Italy, in particular, will

be -counted on to counter-blockade England; to intensify their operations' in the Near mist, N1.oxrth Africai end Sue" areas; and

if possible, to c xebute a landin - on' the BritIsh hbieland-. ~.Japan will further intensify hr ilitary and. political strate gy- to subjugate the Chiang Kai-she k Regime in' hiP'aby

exploiting the-~ results of th;. oporatioris ,gainst the: Uited

States, Great Britain and the N~etherlands ,to hilt: th'e flow of aid to Chiang Kai",shek and to destroy Chinat'fighting-. power;

* by gettint full control of the foreign cone.ossicins ice: hina; by

guiding and utilizing the Chine se residents' in 'thy; 'oSoth Seas;

and by innnsifying -operatjions 'aoainst Chi .

6. E v ry effort will be made to pre'vent . th6e - outbr'eP.k of a war with the Sovie t Union during the opora tions. in the South-

* emn areas,

* 7.' An agreement not to initiate 'separate peace, with the United States and Great Britain will be made with. Germany and

Italy. Also, plans will be made to avoid making peace with Great Britain 'immaid.tely in the event of her surrender, and

to make her induce -the. United States to makea peace;' thus ending the war at once,

&.The development of the war, trends of the international

situation, etc, will be carefully studied at all times, and every effort will be made to grasp the f'ollowing opportunities to terminate the war: a.Opportunity to corpleto the principle phases of the

* operations against China, eospecially the surrender

Oif 'the Chiang Kn.i-she k regime.

b. Opportunity to co plete the princip)le phases of the

* - perrtions ageinst the -Southern areas,

* c. *Otportunitios "which' may "be afforded bar iiprtant scn oin the Auro es-i 's it uae' e'ncs ecia"ythe

dowrill of " the E~x gi h.-honilanid: ±d the te'rmination

27 to the Russo-Gerraan war.

Note: There is some evidence to' support the. fact there was early reasoning by Japanese military and political circles regarding a favorable opportunity for gaining dominant diplomatic control of the Southern area and its natural resources as the result of the -uropean war., This view was most strongly supoorted- in 19)40 when Germany overran Holland. The Japanese Foreign Ninistor, in Ppril_ 1940, declared Japan's serious concern regarding any change in the status quo of the Neth rlands East Indies, Immediately after the invasion of Holland by Germany, he reaffirmed. his prc. vious statement in an attempt to prevent any invasion of the Netherlands ast Indies by Gy rmany, Great Britain and the United States, He obtained a verbal understanding from Germany which provided that Germany would have no interest in the Netherlands.E ast Indies, Irven following the start of the Russo Qerman war, it was felt this understanding was secure since it was believed Germany would be successful in its military actions. Throughout 1941, Japan continued to have hopes that German and Italy, if possibl would make a landing on .nglai'd. Chances of this happening decreased following the outbra.k of the - ussoGerman war, In any event, it was considered there was a good possibility of England having to capitulate because of her military and eeoaomic weaknesses due to geographic dispositions of the a.mpire. 4naland's capitulation was considered to be a valuable aid. in developing Japan's dominance in the Southern area,

Development of Southern Opration Plan

To. meet the situation in the South, strength would be taken from Manchuria,. Korea, or organized in the Homeland to obtain the necessary operational force, The units would be gradually transferred to Central and Southern China, Formosa'and Prench Indo-China.

A troop movement plan was established,

Units to be sent to the Southern China area included: the lst

Division (from Manchuria); air service units (main force from

Manchuria); one tank regiment, six independent anti-tank companies

(from the Homeland); and, some of the signal units and line of communication units (from the Homeland and Manchuria) 0

Units to be sent to Formosa included: the 3d Tank :Brigade which would include two tank regiments (one from Manchuria and the other plus headquarters personnel froth thc Homeland); four indepcndent anti-tanik companic-s (fron the Hoinel nd); air units' (ma in 'forces f'rom. Manchuri a); and. some artillery, sign, 1, and line of cominuni- cation units (from th.., Homeland and ManchuriaX

Units to bd .senit t6' the Northe rn French Indo-China area in- eluded the nhth Independent Mi4xed, Regiment (from the,-oeland); air service 'units (main force' from Manchuia); -and s'ome line of' comn- muniation units, etc (from the Hom1and, and Manhuria).

Reinforcement and, establishmrent of air .and sea navigation installations would be made in Formosa, Palau, French Indo-China, Southern China, atce

Istabliehinents f or 'ling; of -comutnication bases and the stock- piling of operational supplies and munitions in -Southern China, Formosa arid 'rench Indo-China, would be speeded up. Fittings n armament for- requisitioned ships would be prenarod. The: Homeland

Land Defense areas and the national air defense would be streng- thene d..

These measures woe activated .iammdiatAy aihd being carried out as scheduled by the end of Octo'be r. 'In t he-be ginn ing of November, the Tojo cabinet de cided to exert furthera.effiorts for the negotiations to .come to a compromise with the Unitdd"-States a The fArmy and Navy would complete their war preparations' by the beginning of Decembers Following the above decisionl on 6 November, the Army General Staff issued the following; order of battle, and the prelimninary orders for the Southern i:rmy and othe rs 0

Southern Army Order of Battle Outline

Southern Irmy Odnuinder: County Genral' Hisai chi lerauchi *Gexr a headquarters outhern rm f (21st Division,-and 21st

Independent Mixed Brigade). 1t Armyit(16th and 48th Divisions and 65th Brigade )o 15th Army (33d and 55th Divisions, sorte units of latter were. excluded).: 16th lArmy (composed of the 2d Division

and the 56th I'ixed Infantry Group).. 25th Army (composed of a

Guard Division, 5th, 18th and 56th Divisions, some units of the latter were excluded). 3d Asir 'GrQup (composed of five fighter regiments, four light bomber regiments, four havybomber regiments,

and one air reconnaissance re giment) . 5th Air Group (two fightr

regiments, two light bomber regiments and one heavy bomber regiment). 21st Independent 114r Unit.

Note: On 27 November 1941, the 56th Division was transferred from the. Hstern District Army to the Twenty-fifth Army. On 1. January ;1912,, the ;38th Division was withdrawn from the - Twentythird -riny, and the 8th Uivi- sion was withdrawn from .the Fourteenth Army to be attached to the Sixteenth Army. The Souith Sens LDt - achment organized from elements of the 55th DJivision operated in the Southern area but was tinder control of the Army General Staff.

Army General Staff_ Assign nnt . of Objectives and Missions in SouthcrnO :ration

The Army General Staff will prypare plans for the attacks

against strategic areas in the South. In cooperation with

the Navy, the Qommander of the Southern Army will concentrate

its main force in French Indo-China, Formosa, Southern China

and Nanei Islands and Palau Islands areas to prepare for an

attack against strategic territories in the South. Order for

the attack will be issued later. In case of attack by one

or more forces of the US, Britain and the Netherlands, the

Commander of the Southern .i:rmy will be able to counte rattack

with the troops stationed in the respective areas, In deal-

ing with the above situation, e very effort will be made to

settle the situation, locally.

,yFor the China "xpeditionary Army commander

In cooperation with the Navy, the China Expeditionary

Army commander will prepare to attack Hongkong with a force consisting mainl" t f too38th .Diviiohcoinanded by the 23d Army c ommande r,

For' the SouthSea Deta chment co mm'andler In cooperation.~ th th, Navy; the. South Sea :Detachmcnt

commander will advan his force to the ,Bonin Islands and

pr'epare:.. an attack against Guam.

On l5 Novembor 191l,. the Army General Staff issue d pre limnary orders, to the Souther. Army commander to execute the following generl operationial preparation; In cooperation with the Navy, he would be prepared' to quickly a tteadk the strategic territories in the Southern ar'ea. The orders for 'attack were to be issued later.

The strataegic .terri~tories to be occupied were the Philippines, British-Malay, every strate~gic point in the Netherland Indies, a part, f Southern Burma, etc. In carrying out the ope ration, the stability of Thailand and French Indo-China was to be maintained to the fullest extent. At the same time, the blockade of China would be directe-d fromi this area,. In occupied territories, mi3litary administrations were to be estab ished for public security, and~ to obtain important resources for national defense and self~ subsistence.

The respective army and navy units coordinated plans and proearations accord~ing to this outline. Imperial General Head- quarters waited for results from the a'-merican-Japanese negotiations, with-holding only the time f or attack. The purpose of the Southern Operation was to destroy, occupy

and maintain important A'merican, Biritish and i'ethorland bases in

Eastern A'sia. The territories planned for occupation were the Philippines, Guam, Hiongkong, BritishMtalay; "Burma, Java, Sumatra, Borneo, Colobes, Bismarok Archipelago; Netherland Timor, etc.

31 In close coordination betwe :n the rmy and Navy, operations

would begin, simultaneously against.the Philippines and British-. alay

to complete the mission in the shortest possible time.

Operations wre to be launched with a landing on Malay by the

advanced units and air attacks on the Philieapines, The main force

was to land first in the Philippinesstaking advantage of the air

attacks, and then in Malay to rapidly occupy theseareas. In addi-

tion, strategic territories of Guam, Hongkong and '-ritish-Borno

would be 1,occupied during the initial stage ,.of the operation,

~ During this First Phase the strategic territories of the Bismarck

Archipelago and Mtherland-Borneo would be occupied as soon as

possible. Strategic points in southern S;unatrawere to be captured

during the alay Operation in preparation for an opertion against

Java. The important resources i.n' these areas would be protected.

Also,a strategic territories of the Nioluccas Islapnds.and aimor would

be occupied.

Upon establishing air bases. for use against Java and gaining

air superiority, that island would be occupiod. After occupying

Singapore, the strategic areas in northern Sumatra would be taken

at the proper time.

Although our Combined Fleet might have to take counter offensive

measures to met the main American Fleet and though Russia might

enter the, war, the Philippines and Mnalay Operations were to be

carried out notwithstanding.;

During these operations, air bases, etc in southern Burma would

be captured at the first opportunity. If a lull developed and cir-

cumstances3 permit, an opera;tion for control of Burma wuld be ex-

ecuted, The strength to be used in this operation. consisted of eleven

divisions, nine tank regiments, two air groups, and othe r.units

directly assigned to the Southern Army. The outline for the tacti-

cal grouping of the Ary and' thc assigned operational areas was as

follows:

Southern Army (a group. consisting of a division, and a mixed brigade fbr the rench Indo-China area)

1hth Army .. Two Divisions.for the. Philippines area. Air Sup- port to be provided by 5th A ir Group

15th Army Two Divisions for the Siam and '3 urrna areas.

16th Army One Division (two more divisionswoudld be as signzed aftcer comltion of othr operaiols to ope rate with'.16th A.rmy) for thee etherl'and Indie s Area~

25th Army Four Divisions for the ' alay area, Air Support to be provided byr 3d Air Group.

-Other Forces

23d .Army : From the chinese peditionary rmy,One' Division for the .Hongkong area-

South Sea Detachment (directly assi.'ned to the Inrprial Head- quart rs) . Three infantry>r battalions for Guam, Bismarck Archipelago,.etc

Action date was to be ordered later, If -the American-Japanese

negotiations were successful, the plans were to be suspended~

Hongkong, Guam and Bismarc< Archipelago Assgnents and Stratery

After confirming the beginning of landings h1y the advance units

:on Malay,.aa group of the 23d Army would start the Hongkong opera-

tions in cooperation with the 2d hina Expeditionary -Flet' The

enemy £1let would be. destroyed first and after crushing the enemy

position in the Kowloon (on' Chiulung) Peninsula, Hongkong would be

occulied. ' Arny General Staff assignments and strategic .plans. for

the Guam and Bismarck Archioelago included: The South Sea Detach

ment would occupy Guam Island i-n cooperation with the tth Fleet and later was to capture the air bases in the Bismarck Archipelago to eliminate a potential enemy menace against the South 'Pacific Islands. When the South Sea Detachment would occupy-Guam Island

in cooperation with the hth Fleet and later was to capture the air

bases in the Bismarck Archipelago to eliminate a potential 'enemy

menace against the South Pacific' Islands. When the South Sea De-

'tachment had occupied Guam, a naval land comba t=unit was to take

over the' defense by relieving the detachiment, Then, the Army co-

operating with the Navy would occupy Rabaul at the first opportun-

ity and establish air bases. Defense of that territory would be

turned over to a naval land combat unit and the South Sea Detach-

ment would return toward Palau.

Air Force Ope rational Assignments

In cooperation with the Navy Air 'o4:ces, the Army Air 'orce

was to attack enemy air bases at the outbreak of war. ' They wre

Ito capture air superiority as an aid to -rmy landing- operations and

to support later land actions. The main objective of the army air

unit would be -the Malay area. At the outbreak of the war, air bases

would be established in Southern Formosa for the Philippines cam-

paign and in Southern French Indo-China for the Malay campaign.

Air attacks were.to start on the date of the Malay landing. The

Army Air Force was to be responsible for the aerial cover of the

convoy's landing force, Air. attacks would be carried out at dawn

with an objective of destroying the main enemy bases in a single

attack, This was to be done to make the movement of the landing

force easier, After the landing, the air base would be moved quickly

forward for close support of land operations.

Line of Communications (Logistical Support)

Southern French Indo-China would be the main advance base (depot)

for the general Southern Operations; Formosa would be the relay sup-

ply base; and the Canton Sector would be the auxiliary relay supply base. Initial supplies for, one ;full operation would be sent with the landing operation supplie s from the Homeland and V\.anchuaria.

The greatest portion of combat-supplies possible would. be sent to the South, with the Homeland, Manchuria and China as .the source of

supply. In China, self-subsistence would be emphasized and strength-

ened. The relation of the China Operation with.the. Southern Opera- tion provided for coo~neration between the Army and Navy in maintaining the present strategic situations. After taking. care,,of American,

British and other enemy powers in China, efforts would be turned

toward the subjugation of Chiang Kai-shekis power., In. case a

Russian invasion were indicated after the beginning of the Southern

Operation, necessary strength would be transferred to the Mlanchurian

area as needed, 4Lt.the sale time, occupied territories in China would ;be readjusted and important areas maintained to-check any rise of enemy power.

If America should coop:rate with Russia: in the North, or if tho

Russian Army should challenge us by herself, the necessary units transferred from the Homeland or China were to destroy the Russian

Air Forces in the rar :astern Territories..

Proposed Southorn Operation Military Administration

As soon as the Southern operation t~as begun, a military administration would be enforced in occupied territories with the responsibility resting on the Army in the specific area of operation.

This policy was established by the Conference.. Methods and policies of the military administration were developed for. the purpose of restoring public security, rapid control of important resources for national defense.,: and protecting ,scl-subsistence for the army engaged in the operation. As an aid to enforcing the military administration, the existing government organization and public customs would be utilized and respect as much as possible. The Army of Occupation would secure and develop important resources for our mobilization program if it did not interfere with the operation.

In securing resources, and maintaining self-subsistence for the

Army of Occupation, full consideration was to be paid not to dis- turb public welfare and not to jeopardize the pacification service.

The nationals of America, Britain and the Netherlands would. be directed to cooperate with the military administration. Those who did not comply would be asked to leave or other measures would be taken, Current privileges for the citizens of the -xis Powers mould be respected but any increase in their number would be re- stricted. Chinese merchants residing in occurpied territories would be required to comply with Japanese policies and to break their ties with the Chiang Kai-Shek Government. The native national of any country would be taught to rely upon the Japanese 1 !txny.

Jam nese people who might desire to move to occupied. territories after the operations begin must be highly qualified. Those who had previously lived in such territories would be given preference.

Division of duties between the Army and Navy in military administration of the occupied area was decided by the respective departments in Imperial General Headquarters. The main responsible territories of the irmy (the sub-responsible territories of the Navy) would be Hongkong, Philippines, British--Malay, Sumatra,

Java, i3ritish-Borneo and Burma, The main responsible territories of the Na.vy (the sub-responsible territories of the rmy) would be Netherland-Borneo, Calobes, Moluccas Island, Lesser Sunda Isles,

New Guinea, Bismarck Isles, and Guam, CHAPTER IV

F'irst Phase of the War

PART I First Stage (December 1941 - June 19hi2)

Decision as to Time and Date. for Bepyin ing ar

On 1 December 1941, the Conference decided on war. The Imper-

'ial General Headquarters then set 8 December l9).tl as the date for

*its beginning, reasons being:

1. From the Naval Operational poirt of view, Japan had

little hope for success after March 192 because of the

difference in Naval strength between Jap~n and the

United States,

2. 'Any delay in the beginning of hostilities- would mean

a wasteful use' of li_ id fuel depleting critical fuel

stockpiles which could not be replaced unless the

operatii ons plan for procurement from the South were

started. It vas estim_ .ted that if the beginning of

hostilities were delayed until after March 19h2 even

the fuel demands for the first phase military opera-

tions c6uld not'be meta

3, It would be disadvantageous for Japan to delay begin-

ning war''if she expected to complete the first main

step of the oper'ation (expected to take at least five

months) prior to the spring of 1942. 'That would be

the most 'suitable time for the Manchurian Operation

considering the possibility the USSR might join the

war in the North.

h. It would be disadvantageous 'ffor Japanese forces if

they 'delayed operations since the enemy would have an

opportunity to accomplish full preparations for war

in each southern district. 5. January and February were not satisfactory months for

landing operations because of seasonal weather con-

ditions in i!alay

6. 8 December seemed to be the most appropriate time be-

cause of the favorable tide and moon.

Because of these reasons, 8 Decemboer appeared to be the last

favorable opportunity for Japan to launch military. operations.

A critical decision had to be. made concerning the Japanese-American

.negotiations. -then in progress., The Conference made its decision

to start war since there was little hope that the negotiations would

be completed successfully.

Following this decision. the i-rmy General Staff issued the

following orders on 1 December (the same day) regarding the begin-

ning of War.

Summary of Orders, Issued to Southern Army Comm.ander

Japan has decided to begin war against the United States,

Great Britain, and the Netherlands.

The Southern Army commander will begin attack operations

on 8 December. If negotiations between the nited States

and Japan are successful, operations will be ceased at once0

Before 8 December, the Southern army commander will

carry out the following orders:

(1) If we are attacked by the enery, we will begin

operations at a suitable time in cooperation

with.the Navy 0

(2) If Great Britain invades Thailand, we will also

enter Thailand at a suitable time, in coopera

tion with the Niavy,

(3) If. enemy planes repeatedly reconnoiter our im-

portant positions and. convoys, action will be taken against them.

Summary of Orders Issued to China expeditionary Army Commander

The China Expeditionary Army commander will attack Hongkong

with a unit consisting chiefly of the 38th Division under the

Command of the 23d Army Commander in cooperation with the Navy.

Operations will begin immediately'after receiving confirmation

on the beginning of the landing and the air raids against Malay

by the Southern Army.

After attacking and securing Hongkong, a military administration

will be established.

Prior to 8 December, the China :expeditionary rmy Commander

will carry out the following orders:

(1) If the enemy attacks before the beginning of

war, they will be int rcepted at an appropriate

time,

-(2) If enemy. planes repeatedly reconnoiter our

milita ry mrovements, iemediate, acttion will be

taken against them

The China Expeditionary Army commander will. eliminate the

Tenshin-,British Concession, the Shanghai Joint Concessions, and

other properties of the enemy nations in China. If it becomes

necessary, military authority may be used.,

The South Sea Detachment commandr was ordered by the Army

General Staff to attack Guam Island immediately after 8 December in cooperation with the Navy. After the capture of this island, the strenrath was to be assembled on Palau island -to prepare for the coming 'operation againstl abaul. Alternate Plans for the Malay Attack

Plan A: If the enemy air force were not as large as anticipated, it would be possible to carry out the aerial annihilating attack simultaneously with the landing operations of the " ddvance Army Group.

Plan B: Since the landinc operation , gairst the northeastern coast of Malay would be under the protection of a land-based air force whose base was located deep within south French Indo-China and the enemy mirrht increase their air strength in the 11ialay areas, it was necessary to check the enemy by first carrying out an aerial annihilating attack. After conpletior' of this operation, a landing was to be carried out by the 'advance Army roup.

Decision: It had been decided by the Army General Staff that the plan for conducting the operation would be decided according to the war situation just before the beginning of war. On 3 December9 the Army General Staff ordered the Southern Army to use Plan 11A".1

Orders for the Kwantung i.rmy and. the China Expedlitionary Army. Bela ted to '. 'na ncidn ts

On 3 December, the Army General Staff issued. orders to the

Kwantung Army and China Expeditionary Army comnmande s related to

China Incidents. The Kwantung Army was to avoid. border incidonts and if any did occur to settle them locally because the Imperial Head- quarters was attempting to prevent war with Aussi.

The China Expeditionary Army commander.woul~d tighten the present anti-enemy blockade and destroy the enemy will to fight a prolonged war. This plan sought an early settlement of the China Incident.

Sunmary of Operatinal Progress During First StagePeriod

WThen war began on 8 December 1941, the 15th Army marched pinto

Thailand on the basis of the Japan-Thailand negotiations which were begun on the evening of 7 December 1941, and reached the advanced objective at Bangkok on 9 December. Success of the negotiations had been assured by the Japanese Military Attache. Agreement to access

and movement of troops was acknowledged by the Premier of Thailand

on 8 December. Discussions covering an offensive and defensive al-

liance were concluded on.21 0ecember.

In Malay, the 25th Army landed on Songkhla and Kotabharu on 8

December opening up the Southern ,Route.* In the Malay Naval Battle

of 10 December heavy losses were inflicted upon the Bri-tish Fleet

and by the end. of Diecember, Ipoh and i'uantan were*occupied. On

1L and 15 January 19h2, ,Japanese troops broke into Johore and. oc-

cupied Malacca. Continuing onward, thiey, landed and occupied Singa-

pore on 9 February and 15 February. respectively. In the meantime,

the .1th Army occupied: oulmein on 31 January l99x29

The 32d Army occupied Kowloon ,City on 12 December and started

a general attack against 'Hongkong on 1)1. December. By 25.December,

Hongkong was occupied.

In the Pacific area, Guam was occupied bjy the South Seas De-- tachment on L-December and the occupation of Wake Island came on

23 December. On 23 January, Rabaul was captured by the detachment.

During the first Saart of February, the Army .Gene ral Staf. issued orders to the South Sea Detachment comander directing him to cooerate with the Nary and occupy strategic: positions in

British-New, Guinea and Bismarck areas, Main positions of Andaman

Island were to be occupied and also consolidation of positions in

Portugal Timore was to be executed by the Southern 'Army.conmmander.

In the Philippine area, our navy and army units were. successful in their aerial annihilation battle of 8 December. Two advance forces of the lhth Army landed in NTorthern Luzon on 10 December '.1.

On 20 December, an element of the 1)4th Army landed on Lingayen and

Lamon on 22 December. On 2 January 19h2, the City of Manila was captured.

Following the occupation of Manila, the enemy forces on Luzon island-fortified and isolated themselves at established positions on Bataan Peninsula and Corregidor and, fought back stubbornly In an attempt to drive the enemy out of Bataan and Corregidor, the lh4th Ar. t madaL -afiet'ce attack with the 16th Division and the

65th Brigade. However, we were unable to force the enemy to surrender due to their skillfully constructed jungle positions In depth.

Also they were fighting a bitter defensive battle.

Considering the enemy strength and terrain, the JArzy General

Staff realized that the present commitment of the lhth. Army was inadequate to accomplish a rapid occupation. It was decided to have the Southern lynmyr carry out a mooping up campcaign agai.nst the other islands in the Philippi-es and at the same time prepare to :assault

Bataan with superior strength. , o strengthen the krmy in the L-hili~p-

pijnes, the hth Division was sent from Shanghai in february and March and an infantry regiment and a mountain artillery battalion from the 21st Division in Northern China was' sent the latter part of

Februaryr. Both units were placed under corriand of the lh-th M:2 1y

Commander.

Inf addition, heavy siege guns and other artillery units were resupplied and reinforced with ammunition and operational materials to combaft the 'enemy positions near B3ataan and Corregidor. The general attack -upon Bataan was begun on 3 April and by 9 April the entire Peninsulawas occupied.

Then, the l4th Arnny p'rc 9ard an attack on Corregidor hile

continuing its mopping-up camp aign over a wide area.. With the fall of Corre-gidoi on 7 May, the entire Amercan-Philipine Ary on the

Phii.lpne Islands surrendered.

Java Operations Planning

During the last part of December, Imperial General Headquarters received a joint recommendation from the Southern Army and 2d Fleet

commanders that operations against Sumatra and Borneo be speeded ut

so the Java Operation could be moved up about one month ahead' of the prearranged plan.

It was decided that, since Japan was now in a position to carry out its major operations, in the Southwest Pacific, occupationin those areas should be rushed before the enemy had-sufficient time to recorrer its losses and reorganize. This would also improve the over-all military situation for Japan. If Japan could complete the above-mentioned movement, she c ould deal with the movements of the

Soviet Army near'iNNanchiria, which was regarded as a potential active front in the spring.

Taking all this into consideration, Imperial general Headquar- ters accepted the recommendations of the commanders and made plans to take the. next step. On I .January 1942, shortly after its occupation of Hongkong, ,the 38th Division was assig7ned to the 16th 'irmy.

After being reorg.nized arld resupplied its main force was brought up to Banka- and Palembang. Its :astern Detachment (Ito Det) was dispatched toward Amboina and Zupang.

The 148th Division, which had been participating in the Philip- pines Operations was transferred to the 16th Army and reorganized on l1 January although their hilippinest operations were not yet completed,, The 16th Army commander and the 2d Division which had been in the Japanese Homeland preparing for action started to move out about the middle and latter part of January. Special efforts were made to speed up Air Force organization to protect con'voys,

Also, plans for strengthening lines of commnunications were given

top consideration,

In the Borneo area, the Kawaguchi Detachment made a successf ul landing on British-Borneo on 16 December. The Sakaguchi d'etachment

of the.16th Army occupied Tarakan Island on 11 January and Balik-M

papan on 24 January.. The Bastern Detachment (Ito Detachment) which

had been formed from elements of the 38th Division occupied Amboina

on 31 January and Kupang on Timor Island on 20 February, Makassar

(captured by Navy forces) and Bandjermasin (captured: b,- the Sakaguchi

Detachment) came under our control on 9 or 10 February.

During the Java Naval Sea Battle on 4 February, in the Java and

Sumatra area, additional heavy damage was inflicted on the British

Netherlands Fleet. The 38th Division coordinated its attack with h3p the, descent of the Ai r'ori e Raiding Force. :(from lst Air. Raiding

.Group of . the .3d Air Grob}l on . Februuary.and, occupied Palemang on

17 February. Durning.the:last part of FEbruary, the, enemy fleet was

defeated again in the Soerabaja Naval Sea Battle. APt.this time,

Japanese Forces were moving to attack Java.

On 1 March, the remaining enemy fleet in the Java-Suratra. area

was defeated in the Batavia Sea. OQn that saife &y, the 16th Army

succeeded in making a. landing on. Java., After the surropder of the

Netherlands Array on 9 March, operations in the area were comacted.

Burma Operations Planning

Ever since the Burma Operation began, the Army ckneral Staff had

been, anxious to complete its conquest quickly because . of. the strate-

gical value Burma heldas key point in the northern flank of the

Southern area. Burma was invaluable for the blockade, against China.

However, the overall strength would. not nrmit a full-scale Burma

Operation. at the same. time as other Southern Operations *About the

middle of January, war oerations were progressing so well this rie#-

point was reversed, On 22 January, the Southern Army commander was

ordered to proced without waiting for completion of opeations in

other areas. Thus, action to occupy a jor points in Burma was started

much earlier than scheduled.

Before the war, the main enemy strength in Bur .a was estim ted

at 35,000 men for the Army and 70 planes for the Air Force. However,

indications were that Vth e aney had increased its.strength since then,

.At the time of operations, there wer approximately 10 Chinese Divi-

*sions alone the 3uxna-China and the southern. Burma Border. The unit

used by the Japanese .in t-e Burma Operation was the L5th Army (33d

and 55th Divisions as a nucleus supplemented by service units plus

necessary air .force, strength), The 5th. Division was also: scheduled

to be used. in .north Burma because of Chinese Armyin.strength and its

reinforcements.

Reduced. ,o a basic outline, orders for the Burma Operation issued

to the Suth rnArmy by the. Army General. Staff covered two points: 1. The object of the Burma/operation is to defeat the

British Army in Burma and to secure and occupy the main points

in Burma, while at the same time strengthening the anti-China

Blockade.

2. The 15th Army will advance along the line of the

Saiween River in the vicinity of oulmein and. after making

operational preparations will take the main elements from the

area along the MMoulmein--Pegu oad and occupy important posi-

tions in Central Burma.

In the Burma Theater of operation, the 15th Army occupied Rangoon

on 8 March and, went ahead with operations aiainst Central Burma, On

29 April, Lashlo and the China-Burma border were occupied and on 1

May, the strategic points of Mandalay were occupied. During the first

part of May, Bhamo, Lungling in Yunnan Province, and the Akyab Air-

drome" had been occupied.

The Navy carried out attacks on Uolombo and air raids on Ceylon

during the first part of April. They also gained the upper hand on

the Indian Ocean. On 7 MMVay, a naval battle took place on' the Coral

Sea. As a result of this battle, the Japanese plan to attack Port

Moresby by sea was abandoned,

Situation Review and Tentative Plans

By mid-March the First Stage of the Southern Operations had pro-

gressed quite succs- fu-lly and occupation of the desired areas was in

sight. However, we anticipated. that following our offensive opera-

tion American-British forces would counterattack from both the Bast

and West, Imperial General Headquarters made a study of the expected

operations and. prepared a tentative plani of operational conduct. The

Southern Operation was to be completed first, and then consolidation

and regrouping would be accomplished. At the same time, a military administration would be established to promote peaceful relations in

occupied areas and establish friendly operating conditions. It was to be maintained firmly for a long period.

Effarts would be made to occupy the main areas of Central Burma and destroy the enemy, especially the Chungking Alrmy, during tis period.

We. would consolidate our gains achieved during the first phase

operations. with the objective of holding the advantage forever.

the same time, the US and British Forces would be kept on the defen-

..sive by our diversionary operations around the perimeter of the main

occupied area.

Our national defense program would. be enlarged and additional

units needed would be organized. At the same time, the Southern area

would be reorganized and forces reduced within limits allowing above

operations. Objective of this was to develop much larger reserve

forces of. the:Army.

The good results obtained in the Southern ODeration were to be

exploited. and an attempt made to sett:,le the China Incident rapidly

through nolitica2 and strategic methods,

Attempts would be made to maintain the current state of rela-

tions with Russia. At the same time, as a precaution against any

change, defense plans would continue to be strengthened.

The most important problem in the future political and strate-

gic conduct was how to organize and maintain reserve forces which would be available for any e merg:ency. Another problem was the question of where our diversionary operations outside.the defense peri-

meter should be directed.

This tentative plan, prepared in mid-MHfarch, was a guide through-

out the following months and energetic offorts were made by the

Southern Army to a hieve its objectives. In late ay, restoratin

of peace and order in the occupied. areas and the establishment of

the military administration were progressing smooth-ly': ...

ihe' priinary:objective of the irmy eneral" Ita'ff . er turned to est-ablishm nt .of a sta1 .ryl deffensiv situation. ands.ecuring self-

sufficiency.for the army in the eouthern.. istrict, Continued efforts tere .snade to strengthen the Natiopal D ~fenseo Dower in depth.

This was to be done by training, reorganization of units and by secur-

ing important defense rasources from the South.

First of all, by accomplishing ,the defeat of hina and £ri tain

it wa s considered any maij or war effort by the United States might be

discouraged. Also,, .:planning of possible countermeasures against a potential attackr by Russia was necessary. The plans., especially

.46 those concerning the operational order, time, method, etc, would

have to be decided after, a careful study of our National iconomic Capacity and related elements. Imperial Headquarters had to consider

many factors at this critical time including the movement of forces

in consolidation of gains made as well as immediate and long-range

operational planning along with their production and operational

requirements. Flexibility of plans was essential to meet all situa-

tions.

After determining the number of troops to be stationed in the Southern District and perimeter territories, the main body of other units would be returned or transferred to the Homeland. Others were

to be transferred to hanchuria and China. Divisions which could possibly be taken off the line included the Guard Division, the

2d, hth and 5th Divisions which were to be transferred to.the Home-

*land, The 33d Division was to be' sent to China. The .16th Division was to proceed to Manchuria.

Note: After this. had been scheduled, duo to increased enemy activity during the next few months, the only units actually transferred were the h4th Division and a few" units under the direct control of the Army.

The lL.th Army was placed under the. direct control of the . army

General Staff, These cha.nges were established to relieve the . South.

ernAmy of some of its heavy responsibility and aided in the ef-

fectivoness, of the military administration in the P'hilippines. The Kwantung Army was to demobilize part of its strength, especially the older soldiers within limits assuring effect-i;ve defensive and operational preparations in "I'anchuria. At this same time i the China Expeditionary Army was directed to organize the 3d Tank Division. The Kwantung Army was to organize the 1st nd 2d Tank

Divisions. This we part of plan to enlarge the Japanese armored

strength. 1st & 2d Area Army headquarters, Armored Army headquar-

ters, and 2d !.rmy headquarters were to be established to strengthen

the command system in the 1kwantung Army.

The 52d Division was to be demobilized in the Homelan.d (Note:

due to the increase in enemy activity starting in May 2 June this

was.not carried out. the 3d Air Army headquartcrs was to be established in the South.

ern area. Its' nucleus would consist. of approximately five Air Bri-

gades, Its responsibilities were to be the offensive air operations

in India and China and air" defense of important points in :Sumatra

and Java.

One Air Division headquarters and the necessaty7units for it

was to be.transferred to the China area from the South after the

Air'Army headquajrtexs had been. established.

Two Air Divisions were to be placed under -the,command. of the

2d Air Army commander'in or'der to aid and strcingtno -northern .area

aerial and military preparations. Some of then Sou-Lthern :hrca. 'Air

Upiits.,;ere to be .transferrd to.lanchuria with this change in the

organization.

After the occupation of areas wich had been planned and aftr

the First Phase of'the operation, we would either'proceod to occupy

strategic points on the perimeter or adopt a passive role, If

necessary, .we would make thor advanced outposts* in our defense zone.

At the same time, we would endeavor' to disrupt enemy efforts to

.construct key points for thei r expected countrattacks. "heir sup-

ply lines in the perimetcr would be upset through harassing raids.

After studying this proposed operation, the perimenter locations

where the operation would be carried out were set as follows:

Aleutians, Fiji, Samoa, New Cjledonia, eastrn New Guinea, Cocos,

eastern! India, Colombo and Ceylon' (Colombo and %ylon were to be

neutralizod), Actions resulting from this tentative ;plan are de-

scribed in the following sections.

Imperial G :'mral '1ad.quarters prepared an estimate. on current

and potential enemy strength throughoutt t4 o world in May, See

Carts 8 and 9. Estimate of the keov Strength, r 19412

ArsGronnd Streuitk Air Strength Remarks

1,800,000 mn 3.500 active Npected increase for United States (4~3 divisions Frn Lin~e year 2,000,000 men; completed) Planes and about 6,000 front

Pawn area Amq 45, 000 m 1 50 planes

Alaska & $he Arm~y &Navy 10pae

Al u i n Is A rmay 35.000.0 0 menMnHawaiian IQ planes

Midway A & Yg 50 Wines ______1,700 mm -

Samoa US Nlavy 750 .en20 planes

Fiji US &Britit 20 planes 7,000men New Caiednip' USGv & Free,0 rnche 10 planes

*uxmber o menSme ing arrived in Aust- ralia and New Zealand. Austalia350. men 500 -~e approx 2-5 divisions. in Southwest New Guinea & Northern

______Australia. New Zealand J0ivsi0ns) 25planes

Iceland. & US Troops Northern Ireland (1--2 divisions)______2,000,000 mn Number of divisions (a'pproimately 5,000 Front be added, 7-8; and, Great Britain l~ ,±diiions un. planes rnber of planes to b ipleted)added,2,000-2,500 comnaete)______duri gyear.

Nearlast 150,000 men 30pae Nearlast (10 divisions) ~pae

Northern Africa 30 00MWn 700 planes ______(16 divisions) WestrnArica Some UJS Troops WestrnArica indicated

Southern Africa 900 200 planes ______(5 divisions) ______sc British

India 7 divisions;* & 350 planes India Arm,, 23

______divisions)______

Cqrlon (1-2 divisions)

Canada 130, 000 a . 250 planes (5 divisions) ______

Chrt S Preliminary Planning for a Chunging Oeraion During the first part of 1-pril the China 3xpeditionary -'rmy

commander was expected to make careful analysis and recommendations

regarding a proposed China operation piren of the t'rmy General Staff.

The tentative. plan.was drawn up as a preliminary.to major offensive

operation in Chungking when the best opportunity was available.

General objectives of the tentative -rmy General Stiff plan

were developed to take advantage of our successfu1 results in the

Pacific War operations. Special attention was to be given opera-

tions for the China incident. Efforts were, to be made to develop

a largo-scale plan to solve this matter if conditions permitted.

Russian activity would have an important bearing on our decision.

If the situation made it impossible to carry out a Jargo-scale

Chungking operation, previous strategy would;be maintained,. At

the same time, increased effectiveness for the economic blockade

of the Chungking government would be developed by cutting off the

Burma Road.

Confidence of the people in occupdd zones was to be developed by endeavoring to enforce a satisfactory public peace, conducting

political adjustme nts and supplying economnic pressure. Also, poli-

tical and economic pressure were to e;.'directod against people in

unoccupied areas. After cutting off the Surma Road, smashing blows

were to be thrown against the remaining enemy forces.

For this proposed Chungking operation several divisions were

to be transforred from another area to China. Objective was to

destroy the fighting power of the Central Army which was the nucleus

of enemy resistance.

It was considered that the best time to start such a plan would

be following the cutsoff of the Burma Road and when China began

feeling the economic pinch resulting from our successes in the

Southern area. Also, following conclusion of the Southern opera- Estimate of Possible Increases in Fighting Power of US-.British Forces. (May 191t2)

Present Future Remarks

By middleof

j i.. i I 1943 the monthly Due to the resources it } Monthly ou S~ Ltputt 'output will be manpower and material, of approx strength I 24,7 00 .approx 3,200 the fighting U S planes and o planes, will. be greatly in-

+ tanks By 1943 - 3,000 creased, f tanks monthly.

+ I The fighting power may be increased' gradually,, but from the standpoint! Bri itish Monthly output of manpower, 'it is of 1,300 planees. quite a difficult task to increase the number,i all at once.

One division can be organized monthly. However, Ind dha on the aircraft production side there are only assembly plants.

Monthly output

Ca:Tiiada of aircraft approx 500.

output Monthly Australia.:- of aircraft

approx 60,

Chart 9 tions we would have a largo force available which would make the

Northern situation far, more s,-cure:. The.earliest possible time for this operation would. be toward the end of fall.

'Aleutians, Midway and Southe ast Area OOp rations Plans

The Navy Section of Imerial Headquarters advocated the idea that we must occupy Australia because since the beginning of'.19112

American air and sea communications with Australia' nd Njew 'Zaland had been extremely active. This posed a throat since it was apparent United States Forces probably would use Australia a the

jumping off poiht for any future counteroffensive.

The Amy 'General Staff of Imperial Hadquarters thought dif- ferently. Considering our available fighting strength, occupation of Australia was clearly beyond our offensive capacity,

Furthermore, it was argued if this ridiculous operation were to be attempted it would surely fail because military supplies necesr sary for such an operation could hot be maintained due to the shortage of shipping. Lastly, it was out of the question to provide the ten or more divisions which were estimted as necessary to carry out such an operation.

Because of these conflicting opinions the opration was not carried out. The Naval and - my Sections agreed without any great controversy on an'alternative plan, This called for occupation of possi'le American jumpingoff points for operations against our Homeland, Tho enemy was to b6 stopped as far east in the

Aleutians as possible . Australia, was to be isolated by severing the line of communications between it and the United States. This was to be done by seizing Fiji, Samoa and New Caledonia. The enemy counterattack potential was to be gradually eliminated by hitting the enemy bases from the air and sea and by strengthening the sittiation in Eastern NowGuinea area through the occupation of Port Moresby. This method of o'mration would not require a laeg, number of forces,.

Plans wort de o .opecl to seize Port r' oresby and the vicinity be ors; the : uemy had ?.n oportui ty to increase its strength. Howev r,. our transport convoy encounte d the US Fleet in the Coral Sea and a battle: was £ourht betwee;n 7 and 8 Nay. Thou~igh our. fleet losses wereloss than the homy, -cxo lostUTmore than half of our carnier planes which were :essential in the planned amphibious attack. 1ho Port Moresby invasion by sea was postponed as a result..

Next stepJ was to have boen the Fiji, Samoa and Voew Caledonia area o-,.-;ration. Howee r, the avyseddenly demanded that the plan be changed because the Com nnder in Chieof of the 0 ombinod Fleet had insisted that an occl.ration of Midway should be carried out before the.,o! eraltjo against the reviously 1rertione..d three islands.,xhe Na~y stated it would need only an infantry regiment to carry out this task. The Army disagreed with saich a cha ngeo in the orearationa.l -,]..ar.

Following negotia^tion , however, the Army General Staff acceded to the Y!._07 demand. The re v sed plan of ope rations was in two phases. First Phase of the Oceration -;was to be in the direction

of the Aleutians and h'idwaTy. Second Pha-se wowuld be in the-:direction of Samoa, Fiji,

and J'eo C l.edonia.

The Armny decided to employ the North Sea Detachment (one in- f antry battalion, one .n ipeer c ompany, both under Major Hozua'ri) for the Aleutain Op~ra tion. The Ichiki Detachment (one infantry re gime nt, one engineer coran, a^nd one ATicompany, all under

Colonel Ichiki) was to be used in the Midway Operations. Both of those units were to operate ndr I nv, tComand'. -hoW 1Navy had already decided to carry out this omertion using the ma in body of its Combin~d Fleet.

Principle Orders Issued to the. North Sea Detachment commander:

1. Imperial General Headquarte.rs has -planned to occupy the We stern Aleutian Islands,

2. North Sea Det achmegnt commander w~ill coop rat a with the

Navy and be respornsibole for the attack and occupation

of Adaik,. Kiska and. Attu,

3. ,fter the North Sea Detachment roaches the assembly

point., the. detachment will be. under the Commander in

Chief of the 5th Fleet..

Principle Orders Issued to the Icha.ki Deftchmnt:

1. Imperial geoneral Headquarters has planned to occupy Md wayd-Island,

2. The Ichiki -Detachment will coop~rate with, the Na' axed

be respeonsible for the attack and the occupation of

Midway Island,

3. Afte r ,theoh1i leta chmnnt rech the aze ssemably poiant,

the detach ent will be under the co: riand of the Coin-.

mander in Chief of the 2d fflet.

Our Combined Fleet moved into the I idwnay area with its main body and into the~ Aleutians 'with smaller. units during the: first few days of June to carry out the occupational operation.

On 5op Jur ne;, t ns our wF lere et tin ppth d e Miiidw rv~ d area w as d efe ated andla

Imediately, the convoy to the 'deutians was given an order to return. This return order was rescinded and the original landing plan for the Aluticans was modified, with Adak Island being dropped as an ob~jectivo3 In view of the Midway defeat, it was. considered too risky for our remaining na val .units to covear a .landing attempt at Adak, lhe landings. on Kiska and httu were completed successf ully on 7 June and 8 Juno, res ectively. Asa result of the '4idway Sea Ba^ttleour Fl:,0t lost the mjority of its aircrift cariers 'This bwas our if rst 1major naal. defeat *in cc the beginning of the war. throughout the ?aci.fic and

Indian Ccean: The loss of our.. of orce tutp ^ heavy handicap on

our :tactical 'opertins' causing us 'to Tvoid '''ry positive o funs.

ivo movemnts. 'In T iew of Our i' atioiral conomic Cap citywe

could not hope to regain our. son 'power during ' this long term opera.- ton~

The Ichik1j, .L~tchrnnt was returned to direct c'6ntrol. of the

Army General Staiff after reaching ()miy Island by orders issued

on 12 June. The ?orth Sa Detachment was plazced. agoi.n' under direct

control'.OfI the' : army Uenera l Staff after, 25 Juneo by orders i'ssuo d

on 23 Juno. They were relieved, officially, of. their duty to

occupy ' dak arnd were orde~.red to aid in security operatio3ns on Attu,

Now Calod 3n .aFjj, Samoa Is lands and

hile th) NMidway on:.d .$leutian ca1maigns were ?-)ing carried out preparations for te .Fyjji 'and Sao ;o5Island tler ations were being made.' The: battle ordors were ssued. on 18 Moy for the 17th Army

.ne .ude:diteand the followig pointss 1. Impe.rial 'Genral Headqurters his planned to occupy the

iinprt nt points of°Nb aled:nia, Fiji , Samoa_ and to

occupy Port ic rorsby.

2.Te17th Army c ommander will co }r .r^ to with the l'a vy and acccom fish -the 'av"-.men ±oned ini sions, Objective of 'the ice iCalcd~oni . i Iand Surmd::Isl ands on ;ra.

Lion' vas to ' rit arupt' supply lincsbetwe:n :the United States and

Australia by ' occupying and repulsing any enemy .countorattacks from that direction.' The: A.rmy employc d th. main' body o .the. 17th Army for this ope rat ion. The hist Infantry Re giraent l(5th. Divis ion), the Kawaguchi Dotachment (three infantry battoj..ions of the 18th

Division)., and the scuth Seas Dotach , -nt (three infantry battalions of the Seth Division) made up the ma in army force. The Navy employed the 2d Fleet and the 1st ir FJeet,

Staging area for the N.ow Caledonia attack force wa s Rabaul whore th e force was to ass mb:le. during the .last part. of Juno. Units feor the Fiji arnd S inoa camupaigns wore to gathe r at Tru.k

Island during the first -part of July. Support operations by the

Combined Fleet were to begin around the first part of July do-. pending uppn the operational situation of the fleet. Objective of the postponed, Fort 1oresby opratio-n was occupation r f that area.. This was olanned to. control the Coral Sea and to cut off the key enemy offensive position which might be used against the.iEStern Now Guinea area. For this operation, the army employed oth relements of the l7 th Arxmy, The A"oba. Detachment (three Infantry Battalions from the 2ciDivisionl) was the nucleus.* The Navy used. part of its 11th Air s leet and the

4th Fleet, The1 attack force was to be statge at Palau during the middle part of. Juno,. The Fort Morosbby operations were to start after the New Gale donia Operation and befnre the Fiji and

Samoa Operations.

Preparations progressed satisfactorily for the rray, but duo to the Nary d-feiat in the 'Midway Oprtions, Imperial General

Headquarters was compelled to postpone the Fiji, Samo a, and Now Caledconi.n Operations f -r appproximately two monthso Some of the scheduled attack units were delayed and sent to the 3.ismarck Archipelago area while the main body was sent to Mindanao and Pauau to await further. orders. The units were to proceed with operational preparations and training at, those places. Operational Conduct for Southern Armcy Following Completion of First Stare in Occuational Oerations

ObjectiV .. s in the first , ta gof th':_~ r't haseo 6f outh arm iyoperations were compilated in Jude'. The 'APrmy' imprel Staff, issued new orders according to the prearioj ulyc seis od tetative plan orb tthe comin 'duxies .for tho Southern .:rmv . ,This was dlone during the ls tter car't of June0. The orders were desi~.ned to be adaptable in rieetin asfriy kind of situation, which 'ml it arise

Follow ing the s lirr en der of the Ph liroi es, th ;l14th Ary was withdrawn frbm the Southern' Army an(.} placed under direct cos trot of t Arrth y eeralSta_f 'on 7'June. On 29 June,'9-the

"followin^; prin-ci ale orders we re isSS LED.

Princi ole 'Orders for the S oiftherli Army commander.

1.''TI or6er' to accomplish that' was considere d to be the final esT) o towa,+h rm nrl St ff intended to

establish se lf sujo b and firth control throughout the

occupied. area. Gain s were to be con}:solidated and

-,pre,aratioues i el. to' defeat any attempts to upnset our

control of thne i_ aorta t Southern' areas.

2. The Soothernm.'nnny was to coomaerate with the ,eyand

* be responsible for sec ring the j.: ,,rtant areas in th e

',South: recessary oeratioel prepDarations for sub-

* ugtion cauncai ,ns were to ba, made -for use arainst

imiportcn,t 'postions on the outskirts of this area.

a. Defense olens wo1uld be comi-l ee4 in BurL a, alay,

* ' Sum~tra, Java aind pritish- orneo, including

military a aln istrations .

b &A bcordinP.-a i n tow th'cy e Mutual ;: Def-ensen J th Ad.flli ances,n 'f co-oe

Pressure;7 n 'a';a:n stn ocChungkin iac. gh ough the blockade

would be continued from - urma', iFrench' Indo-China and Thailand.

d. Offensive air operations w-iald be conceontr. tedc against India and. China. , prations on the

ground would be concentrated aga ilst the inlend areas of India and China, £Nocground cpera ti ons

wore to be started unless c o)eredi0 by sp cific orders,

s . If necessary, cooperation would be given in the defense of area^s under ,Naval acrriinistration. Principle Orders for the 114th Army Commander

The l11th Army Commander- was to~ coeoerate with the Navy

in establishing order in the Philippines. Plans were to

be moads to speed up introductio'n of the rdJIityadi-

stra tion .uon the natives.

Duey to the i ncrease in size of t~he occupiecd area, an a gre e- mont had beon drawn up on 2 June c )vering area administrative

resonsbiitis Th~s c inormdgo ~eauly, to the defensive areas of re sp ons iility.

1rmy-Na yC etral 1Aregiment _.,^ar in; South: rn Area, Defense Rs :)"i'bi4. tie

.stablishme nt by Imperial Ge.neral Headquarters of a defense plan for the Southern area c la rified the co jra tivo procedure between the Army and Navy.. This was decided in the form of an

Army 14 -r Central Agtre ement on 29. Juneo coverins defense of the occuix-ed areaL. The inmortari Southern area sections concerned were those occupied Southern Districts west of Dutch New Guinea. As a defensive ob ecti , the Army and Navy would cooperate by launching attack oTierations of planes and ships to smash any potential enemy c ounterattack plan. Tho remaining enemy in occupied areas Twould be mopped up quickly and subjugation cam jai gns would be initiated against important positions on the outskirts of the de;fense nPerim ter. With: close cooeration between iArmy and

Navy, each important occupied airea woutld- be strengthened and any

Qounteratta~chig 'ensuries were to b: annhilat ;d. Necessary naval. saife"rsuards woi~3Ai'be establishe d f 6r, ac onu::cation in the South 'anid between tho Soizth %Pcl' the Nomo land. The Navy would be res-oonsble fo~r contr'olling and keeping the' sea lanes clear all -along the occupied " as. -Thu Navy would carni- out aerial 'Attacks and subr arine operatins in the L ustralia and the Indian Ocean- ares Sea. manuvwrs rold be 'pl. inod fir surface. f rces to ncount r and destroy enmy.: warships as the oenmysituation llowd.

The Army would .be responsible' for destruction of enemy air power and important mili tary intstallations mainly in the vicinity of Southwest. China and ort oiast India. The Army would cooperate with the Navy in chocking and d stro j 1mg enemy shipping where no-. Cos sary.

Allocation of defensive roc ponsbilitios provided that the Navy would be directly respaonsible for all sea defense, exclusively, and for the ground .: fosse .of Andornr Island,..Nicobar Island,

Christmas island, Lesser 6unda Islands, Netherlands Bast Indies (excluding Java and Sumatra), and Dutch B3orneo. Other are.as were to be the 1rm =Is re sp onsibility. If an opra ti: nal situation required it, the army and Navy would c o ope rats in carrying out the responsibilitie s assigne:d indlividually. For < xamplo, if the enemy counterattacked areas mentioned as being do f nse rosioon- sibilities of the Navy, the A'rmy would provide necessary forces as quickly as -possible to help the Navy* repulse any such enemy operatio n. In such case., the Alrmy would be re sponsible for all grouind operations excepting ri al defense.* The Navyr was to est ablish bloc kaded amd take action t:o pre went' enemy Passage through such pla.ces' as channels,' etc. This had as'.' its --bjective the preovention o.f submrines from. oprating in occupiedl areas.

T~'such blockades Tier~ to bb, establ shed in areas under Army

control, conferences were to be .hed wth the ?Pe:al co~m tinder

~ncerned.

The Navy was .to , be responsible Lor the sea defense of the main harbors (Singapore,1 ai aa Sooi'abaja, ata vi a Dvac, Rangoon and Penarng) in the imn"ortant'Southern District.

'For its sea blockade an1,hrbor d!eense opoxati -)rs, the Pmav was authorized to-, stoblish grot? cdefensive installations at

necessnary points in ' the roeplnsible areas of the 4my after con-~

ferring with the .-'cal comimander c oncore..Aso, the Naivy was authorized to place, necessary Naval personnel in such areas, Th sc rt of vesse.lsr underAyrsponsibliy a't'b

decide d between the army and -'avy Cro aners co;ncerned. Army forces were tcobe used in coiprtien with the i'iav fr the defense of' Timeor. By the mi.ddle of .ugust, the entire island

(except air defense) was to be the Ary's re)sp -sibility using its cur-rent strength in element consi stinv of an Ifantry att li. n as its nucleus would help in thie defense afte r the zriddle of' Aug;ustU.Th0 entire fo:rc , of the Army on Tjmor was to be withdraw~n by the e nd of the ye ad uNoes s a great change decveliored,

Bstobl shment' of Air Bases 'in Im'oortontSouthern Zon'es

ALir bases we r on:c.ossary in thy, c m-Lnrg; rnlrati -,ns' amdf.. r protection of the imaorta!nt Southern areas. From June ,on, °air bases

were being set up in such rlaci as Singapore (key base) French In o-China, Thailand, Surma, Na.ay, Sumatra, Java and t.), PhilipM- pines. Planes w re toy be roi'areclad sup:plied at these local bases. It' was nec essary to indreaso, the local su ily capacities t satisfy .requirements of thOe;b srs,,

Asir lines wore. to be establishoed with special att ention ipaid01 to security for the. main line. s which would provid liaison bea twoon the military. air bases and r outes of communicatio n within the Southen Co pr Dspri.ty $phere * These air. lines woare ,to 'be:

Is*Forinosa- -Phii irines. -Iastorn Borneo- -Jatva. Line

2. Porraost-, -Phillpin s--Weast..rn 3 3 -rn o--SitgapoLine

3. an -- mthvcin. Tench Indc_) China- Easto rn iMlay-

Sumatr -- Javaai Lino 4H. ongkon ;--SNorthrn. French Indor-- ...n-.Thia ilr.nd---=I-cst rn Mala.-Sumaatra Line.

5"Philippit es-.South rn French Inc Mhi a--Thail an'-

Eurma Line

Line of Cornuncat .or (Lo istica3. Supprt)

The Army Genral Staff acte . upon thu. f' Ilewing pri nciples regarding the Line of Con~nunication and traffi c during the latter part of June in re orrganizing the Southern ArMy.

The Southern :4.my comndri n was to stre;ngthen his lo.cal s:;lf. support to cut down on his noced' for supplies from the Hbm :and.

This was to ease the load on the Lines of Com unicatiL'n. $'aigon and Singapore were dosignr'tocl to be the no:rmal supply b^ses for the Southern hinmy.

The Southern A+rmy coramander would control the railway system in the occupied? area, after the completi -n of the transportation nettqrk it was oxtpect. thayt the dcmands for milit-ry .transportation, resources (raw aterials) transportatio~n, and esvsential. public transportatio.n c o'eld be m-t. Ex~opt f r ro nte aro ^S, the railway system was t be the .principle maoth :.C. of land transp orta- tion. Because of critical ship.-ing short ages, it became necessary f or I n orail G:;eral He;adqu~rters t exerc ie extremely close c.ntr l of ;hi':s oprating to an from"the Southern area (except.. in, Saigon and- Sinjap ire ) carrying op r ti onal icarg to fulf1ll requirements as ordered by Imperial ficaciurters, Thou gh ships use, wor;' o esir nated an~d honnl d in oporati.:ns by the Shippin .

Transportation c tnmaC,t eore 'isp'atche'as boin- under direct ccontrelr of Inioexial G= aHodqu'tcrs Mhswst ~e ftae commanders from taking- control of them whilcey r-re .we.oiporat.ng in their territories. The shortage of transports was an opra- tional problem in the consolidation of occupied areas. The Sou, the}:rn ihxay coimnande'r wG s re spo:nsiblD1e for -t -io inter-area transportation in the South which inicledl transportation to the Navel Aministrat i ,n area and thQ Phil i-p ine~s except f or areas speoified later. In addjition, he was responsible for intro "area transportation (except the PhilippDines). "For this purpose, he was authorized to use the local agencies of the Shipping Trans- portation c oirnnand sta tioned in the Southe~rn arcs,

Th Southern Lrmy crnmnd r had su,:ore° °Jurisdiction ever non-military c mm'oxinictio:ns (Signal) in the occupied areas.. Each subaordinate coy oma ndr was responsible for hanl~ine- these coirnuni- cations in his area, Steps were to. be taken by the 8 outhorn Arr commander to reorganize the non-niiitary c omitunications (signal) to r, lievre the army Signal Unit-Is responsibilities,

The Cheki a? -ianz si Opration

During this samei period, US iry ri anes took off from aircraft carri.ers on the Pacific Ocean arnd attacked 'ie Homeland on 18

April while orreoute. to bases in China.s Imperial hea^dquarters decide d to prevent. such enemy activities by occuoying enemy airfields in Central China at Lishui, Kanhsien, and Yushan. The china Bxpeditionary army co. dmander was given orders during the latter ~art of Aprail to begin op~erations which would destroy those ma rn bases, spci 1.1y in tho cAirction of' Chokiang. Th ; Choki. nr;- K n si ;Pora ,,pis were begun on 10 June and c.~ram plated by o '1~ Jutly,

nbto n tio'?1'' ^;'V2'n',tS Con Ll 3 C lur'in :this re r i d ncludA:

thJan-lrnch coChina.''PDcPao'8 iocobo r;Jn-ownyIty

Non-So;,rao-Poaco Pact, 3 . ,coxnbQ;.r; 4.nd, J 1an-T1 al ,Offcsivo and Daft nsiv3. llaincd , 21 Docombr.

.r ;,, . .L I T Ii Second Stage (July- Do cemb ir 1942) Suspension of the Fiji , S- amoa and N;w Cnledoni a Operatio:ns Thu situati :) was quiet in the. Srouthw s t area urn the Ilst half of 1942:0H ?sever,' enemy c ouatrttcks became, more and more intense in the Southeast A major 1evel:o pimont broke when a strong enemy force assaulted and occupieQ Guacalca nal and Tulagi Island on. 7Auust,

Boecause. of the heavy losses, sustained .in the M~idway Sea Battle, our remaining Combined 'l :et fo~unt' it disadvanitagcous to attack enemy land bases after July. This. put. Japan in a bad operation. n-ositi0n.,.. A plan to reduce this. disadva nta ge was develop, Cooperation was to be undertaken- with -erma^ny and Italy in connection with their 'operations in Northern =-frica and possible Near East. operatio~ns.* This plan, which was believed more favorable for our. surface forces, called for our. destroying enemy ships and into rrupting enemy reinforcement eff orts throug~hout the. Western Indian Ocean area, In July, Imprial 0 en rah Headqcuarters, after considering the above factors, de~cided to susre nd the sec onCd =)e rations a'; inst New Calo donia, Fiji, Samoa and Midway, On 11 July, the 17th Army was relieved from its assignnt to occupy New Caleddonia, Fiji and Samoa. Now orders were issued for it to .occupy and secure

Port Mloresby in a coordi.nated land and. sea ope ratLion with the Navy and carry on with its campaign toward astern New Guiznea. Chianpes in the 17th hrmy's Ooratio'nal Outline included: 1. The Objective was to be occupation of such strategic

positions as Port Klorsby and such mopping-up orations as were necessary to be carried out a ainst enemy forces

in eastern New 0uinea. Control of the Coral Sea' was to

be directed from these areas plus the ,Selomons.' 2.-. Strength to be -used consisted of the main body of the 17th. Lrmy (approxi matelysix:infantry attalions as the nuceus);- a unit cantered or, the 8th Naval Fleet; and,

aunit coentred on the 25th Air Flotilla.e

3. The general strategy to be used called for the main body of the ir to capture Port Moresby and airfields

in the vicinity from the directi:)n of the Buna-Kokoda

Road area. .Part of the Army unit was to land,*if noeces- sary, in the vicinity ref Port .rro sby to help thy; .round

advance during its final3.eta, es. , The; Navy was to

destroy enemy air nowor in tho' Port iionesby area, chock enemy ships in the -North Coral Sea , ^nd protect our transport units. It was to cooperate closely..in sup~port

of- ground ra:or nts. Durin or aft, r the Port Moreosby

offensive o eration, Eastern Now Guinea. and other

stratogie' oints, were to be socur ;d and occupied at appropriatetrs Among these, Navy units., composed

chiefly of the Navy Land' Force and others, were to

occupy outlyino islands etnd strata;gic-p pints along the North coast.

On 21. July the 'South. Sea Detachment began T.din g on Buna and started the Eastern Now Guinea O0prtion ..

'Cndc of Guadalcanal Operation

The I my General- Staff of Imperial Gen ral Headquarters had

evr been informed by the Navy Section regarding a Naval Farce stationed in Guadaalcanal, Tula,]., etc. of. the Southern Solomon area.

This information was first. received from the Navy Section when :reports were. received revealing. an enemy counterattack in those areas on 7. August.

.Approximately 30 enemy transports escorted by 2 aircraft carriers, 1 battle ship,1 10 or mre cruisers, and a large number

of destroyers started landing operations on Tula gi. and Guadalcanal

on 7 .ugast.7lAfter pushing back our units consisting of several

hundred soldiers in Tulagi and 300 soldiers p lus 2,000 airfield

laborers in Guacalcanal, the ene;my occupied Tulagi Harbor, and

the Naval A'.rfiold on Guadalcana.

After the 1Army General Staff received this report, the ichiki Detachment (in reserve on Guam Island) was ordered on 10 August to

proceed to,) Truk and becomea part of the 17th Army command. The

Aoba Detachm ent which had boon transferrer' to the l1hth Army on 20

July was orredr~c returnee to the cornrand of the; 17th Army. On 13

August, the 17th i*:rmy commander was ;ivory -rc'ors to continue operations _in 1 asturn Now Guinea ami., simultaneously, recapture important Solomon Islands areas.

The 17th Army was to executOof:fens ive operations ag.-ainst Po:-rt M~oresby according to -plan, as quickly as possible. It was to recapture, important areas in the 8 olomons, in cooperation with the Navry, This was planned to take advantage of the successful ro-

sults obtained in the First Solomon Sea Battle (Battol of Save

Is]a nd) . In .th t battle, our 8th Fleet claimed sinking of 8 enemy cruisers and 6 destroyers.

*The. strength to be used for these operations included the 17th Army (composed of appro)ximately 13 Infanr atalions ), and a unit. com- ose d min-Iy of the 8th Fleet and the 11th t ir Fleet plus

main strength o-fthe 2d and 3d Fleets, ?art of the tiresenit 17th Army was t' depart t nce and attnack the enemy on Guadlcanal in coo.::eraticn with the Navy. Strategic *points on the island, especially the airfield,. were to be recapntured.

Efforts were to be made for an attack to quickly recapture Tulagi. The Port Morersby 0ffensivert Op eration was to be carried out as planned and the campaign against iastern Now Guinea was to be continued at the sane time.

The first echelon of the £chiki Dotachnment was transforrcl by

destroyers and landed on Guadalcana). 18 Augst .'in rattack was

launched on 20 A"ug;ust against th enemy but was. ineffective On

this same date, a :;proximately 30 enemy planes st rroc operations

from the Naval. airfield ti ch they had captured.,

The second echelon .of the Ichiki Detachment and~ a cart of the

Kawaguchi Dotachmont were to land on Guadalc anal on 28 A.1ugust. The

detachments bcoing transported wore assaulted on the s~mu clay by

-planes and suffered heavy damages... This interruoti:?n.causes' a one day delay in the landing operations, Those two detach ments had

inadequate signal facilities and contact with Army headquarters in Rabaul had to be channeled through N~vy outlets causing delays and

confusion in operations control,

*The Army General Staff issuA,: orders :gn, 2.9. Aug~ust placing the

2d Division, in the Order o~f ',:ttle for, the 17th Army, It was f or- morly stationed in Java under corrns? of the 16th Army.

The same day the 'jrmy General Staff revised the operational

outline of the 17th army for, the receaptur ; opera tion of. the Solomon

area and the campaign against Port Mo resby by increasing the number

of infantry battalions to be used, by ~ making .atotal. of 18 as the nucleus, There were to be no changes. in Navy strength. Pri-

ority was given the. recapture of Guaalcanal. N'Jxt in ,mportanco was Talagi. This was a shift away from the previous ,elan which

called for concurrent executiocn of the Solomons and New Guinea ope rti ons.

Rabi Airfield in the Milino Bay area was to be secured during

this revised operation.. According to plan .after the recapture of the

Solonons, the Navy strength was, to be diverted to New Guinea anid

our air forces were to attack enemy air forces there. Ground forces were to advance 'southward from Kokoda. They were to =ccup3y the Prt M:resby Ai=rfieldcs Group in a j,-oint o era-- tion with the Task F'rco which was to be lan'ec'.d at Port Nerosy through cooperation of Ar and Navy EJniitsA

The Kawaguchi Detachment reinfiorced with three Infantry Bat- talions from the 2d Division (2Aoba Detachment) on 12 SeTlterb r began an attempt to take the airfield but wre .thrown back without attaining their ob jectivu and received heavy losses. The enemy force was estimated to be a US Marine Division, with a strength of Gqproximately 10,000 men and this number, seemed. t,-) be

Sincreasing-.

During the middle part of September, the South Sea.Detachment,

in Eastern New Ginea routed two enemy battalions. after cross- ing the steep Stanley Mountain Ranges, the Deta.chmaent prepo red

for the next step in its 6oerati.ons.

On 18 September, the Army Gen ral Staff made another change

in the operational outline for conductin operations in the South-

east area.

Following an increase in Army strength and materiel,

combined Army and Navy forces were to capture Guadalcanal

Airfield. While waiting for reinforcements, the Navy was

to pr;ent enemy personn el 4n.d supplies from being brought

into the olomons.

Before the beginning of the' Port M.;:resby Operation,

Sabi Airfield was to be taken by joint action of the Army

and Npvy.

The Navyrwas to strengthen and complte airfields in

the Solomons and Eas trn Now.Guinea .

Aifter recapture of important areas in the Solomons and

Eastern Ndw Guinea, the following out1ying points were to be

secured. *Solon on Island~s (Inclucles Sarn. ritDual and Ronnol )slandc') Louisiace Arch ,.lagq

Rani, Samarai Vicinity

Port 'ore shy Vicinity. (incluc in2, KID Yifil) *The coastal aaof. ?_pr Gulf wa s ton be 1'r

if the situ ation poimitted.

*After attack ; rer^rtions fior Guadalcal. had been made, the

17th Limy (with the 2d Divison as. the nucleus) starte d an attack on 24 October. Due to enemy air suerieerity,, tho attack was a failure,

In Eastern Now Guinea, the South Sea Detachment. encounters d supply trouble on the Stanloy Mountain Ranges. Causes wore given ~s enemy air superiori ty and rugged, mountainous toerrain. The operation was a failure and the detachment was finally ordered to withdraw back to the right bank of. the Kumusi River.

Situation Review and Plans. (October l142)

The Arm:y General Staff studied the situation and concluded that

China, the Indian Ocean, the Southwestern and Southeastern Pacific

Ocean, or the Northeast area would be the enemy counterattack area.

Necessary countermneasures wore essential to moot the throat of enemy counterattacks apparent in each area. However, it was osti-- mated that the enemy would not attempt a large scale air raid operation from the China bases as yeti. This view was based on the enemy's difficulty in building up the necossa ry number of pilanos and amounts of fuel Lso, it was considered the development stage of ei-my air bases had not advanced far enoug.

Weather conditions in the Aileutian Islands ;probably would pro- vent the enemy from o,,ening up. large scale counterattack operations except during March, April, May, September, or October. .

The Southeast Pacific appeared to be the m~ost likely position from which the enemy might launch a counterattack. Reason for this w as that Australia and its surrounding islands were conn ctcod to the US by a chain of islands arnd made the Southeast Pacific a very formidable position. Throughout this area, the; enemy was able to deploy lax go air,\ ground md naval forces. This allowed thorn to threaten our c ommnand of the sea in the WestV Pacific, recapture our Southern Occupational area, and occupy our South Sea Islands.

Air raids could be carried out easily ag ainst our ,..+p;rtant resources areas.

After a thorough study of the situation,. we decided.: tha the enemy probably would attack this Southeast Pacific area and w'ould start a regular countoeratt ck after de ployin. strength This was conusiderod to be a potentially decisive battle between Japan and

US forces in this strategic area,

Taking the above factors. into ccnsieration, the -r my Geral

Staff planned to set up a command system to s trong th n the fiht- ing power for the Southeast Pacific area and esecially for op rations against the Solomon islands. The 8th Area irmy was to take charge of the Southeast Pacific Area Army ope rations in general.

The 17th army, under the c c nandc of the 8th rea -army, was as.- signed the, Solomon Area Oerations. The newly established 18th

Army, also under the 8th Area Army,, was assigned the ew Guinea

Area Operations. The st Division and necessary units under direct Army control were to be-o reinfcrced f or another attack against

Guadalcanal, Also, ncessary. JAmy Ad: r Force Units were to be as- sigJne d.

It was believed that several more division would be necessary to carry out the operations in the Southeast area, including

New Guinea, However, the choice of divisions and areas from which they would be taken were to be decided only after careful overall study -of the operational situation for the coming year.

68 0Sutheast';1rea Qetins1'ober .- Dcciber 192)~

About the midd'le -l Iovembr, in anoff 'ort to .rc uilVthe strength of the 17th. Frrmyrwhose offensive on ?h4; oblqr had failed,

the Army General. Staff ~.tantried sending by con ;oy ,ppczio

fast transports with."reinforcements an-c'. Su'1 i s aHw v; the shi:ts were' sunk on ih Naomber*. Neither sUpr)?:y or ersorxnlel transports got through b cause: of the heavy enemy, air to ombarch ient.. Attempts to use small craft also faile d, making su pply for Gua dal -

canacl most impossible. It was dlc ided that thoe l7?- h Army should maintain- its present positions until .,the 8th. 3 ra. i-my hae an op:- ?or'tuinity to nr e are for a ? argeo-scala o ratjcn., Durinig this

time effectite sir o,.rations proparations ware \t4 to secure

imrportant positions in both the So"lomoons an,-. Now. Guin a.,-.m ortant

in 'the proe34.in:nry plans for the comiing ory tion was the fact that maj.r pints near. our -present positions on. Guadolcanal 'should be secured Strategic positions at Lao, Sal.-maua , and Bung: ware to be 's&cu ed in Now Guinea. ir bases ware to ha' constructed on the Solomons r gar le s of, cost. On 16 Novnbr, the Army Gpnral. Staff. iss ued -the; Order of

Dattla. for _ he 8th Area Agi y, consisting of the 17th..army (2d, 38th

and 5!s t Divisions aS its, main strength)ad the 18thIArmy (South Sea Detachment and 41st I Pantr'y; Regiment as its main sere igth,) The 8th Area '_rmy c on~xandr was ordered to ceooerate wi~th the Navy in the occupation 'of ihe Sclomons. At the same. time, he was to secure slected positions in New Guinea and prepare for -the coming operation. Mean hile, theNv had decided to employ

a la ,o part of its .Combined Fleet in the coming op;eration. In the overall...oprtion, the Army and Navy ,were ,to coop rate

first in stopping enemy air p:ower in the Solomon area. At the

same .time, o:arati n 1 pre arayticns f£-r. the; Guadalcanal area wert,

to by completed. The enemy was to be annihilated and Guadalcanal irfield to be roca:ptuarcdi Also, Tultgi and othe r strateg;ic parts of the Sol omoris wo to be attacked' and capturocd.

liotheor p~hmso of the .above oycrationi called;.f imprtant p+oints of Noew Guinea to bo socurcK.by a joint . rmy ,rO heI effort, Pre- pairaitio ns wore to be ma!1c,.de3 £ the next operaton in thaIaarea. To gain our :objectives it was nessa~; to stre n th n our fighting power and secure the 'key offensi ve-points on Guadalcanal.

Simultaneously with the Army-Navy effort ""to stop e nemy -air activities, each important occupied posi tione's"d fonsivie. ability had to be strengthened, especially against :air .ttack0o Costruction of' necessary airfields .b the 'middle 3G rt of December

Thenenemyj airfields and areas west' of thbe airfields would be attacked.' and occupied by' using all the strength necessary. After this-, Tulagi and othe' Important parts of the Solomons were to be taken. At the same tint , the Army and Navy would strive tbo establish selected stable operational points in New Guinea,,7 near Lao, Salamaua, and' Bvna. more relay 'and? operational airfields for New British

Island and New Guinea were to be estabolished. On 27 November, the A1rmy"General Staff ordered the 6th Air Division to support the 8th Area- Army. The 6th Air Division commwander was to be in joint commnand, under the '8th Area =Army, ini charge of air "units.

Many difficulties were Inc :,untered in making preparations.

Transportation of munitions and °reinforcements by 'destroyers and smaller craft become very difficult, due to enemy air superiority.

70 *Our supplies steadily. decreased. This .situatio.n cau sed a groat difference in strength to develop'-be twoon our uni~t and thosc of

the eonemy on Gt daloanal : The 8th 1reat Army had oxpcted munition~s t,-.,b:.?tr anisimrted

for Guadalcanal .porations.. They. were needed fc:- ueo in rocaptur

jng inipcrtant po..sitions on the Solomons aceordin zto the operational

outline,. However, .. the Navy was, constantly ncouintering, enemy air

and sea atck,.mAt the same tbane, the. Army had difficulty in establishing airfields. is~voanwhile, the enemy increased its air

*atd sea strength, daily. Imp:erial General Head~uar tors found it vary haz~ardous. and difficult to carry nut .its 'trzterran od plan. If Imperial General Eeaclquzarte rs were toc go a Ice d with the op prtion according. tax the old pelan, it ? a5 indicated that a ship ttnage of 3,000,000 tons must b; newly r quiisitobnod. 'This was not, possible ;because of the effect, it w'ould certainly have on the overall National - conomyi.-Past- and predicted future losses would have a disastr -ous effect on.thQ balance. '.n the National 'obiliza.. tion~iatriel. --of Those. wore statistics l facts. From the ao~ poarance of things,. import aint pots in the r.::a r areas, would be left in very vTherable positions if streng'th' wor~e diverte d from them to the front line. This could be a continuing' ~nc'. dangerous drain on our .reserves.

Taking into considaeration ~these difficultidy, Imperiial General

Headquarters decided on 31- December to -give, up- the' recapture plan for the. Southern Solomon...

Before the above change was made, on 21 December, the Army Genera l Staff. cha ngedr the .:rdeor -.f battl : for the 8th isroa 'irmy.

The h1lst Division, and the 21st Indepeindent MAixoc' Brinae were assigned. The 6th and 20th Divisio'ns were assigned to the 17th ALrmy and the 51st Division was assigned to the 18th Army. Changes in Other Area Operations.Caused by.Solomons Difficulties

During the c prte:rLcQ of November, Indd- Chna a rmy headquarters had been E s ';.ilishe,.d.. Plans were drawn up -c s rengthen the

defense in French Indo-China and the South Pcii.:; at ea by revok- ing the return order for the 5th Division to the Homeland.

Since attacks against India had been suspendedj ;we .anticipated difficulties in the program for the Southwest area. This made it essential to adopt a plan to tighten defense there. The necessary personnel and fortifications were increased at major points along the Indo-Burma Border, and in Andaman, Nicobar, Sumatra and Java.

This was a move to fill a void caused by the transfer of Army-Navy

Air and Navy Surface Forces from. the Southwest area to the South- east, Patrol of the Indian Ocean was assumed by. the Army Air Force.

Burma Area Army headquarters was established to strengthen, the command system.

From a defensive viewpoint, the Lesser Sunda Islands, Tanimbar,

Aroe Island and Western New Guinea (near Australia) were vulnerable spots. On 15 October, to cover these weak spots, the Army General

Staff ordered the Southern Army to divert personnel to these areas.

The 48th Division was transferred from Java to Timor and Soemba

Islands. The 5th Division was transferred from Malay to the

Tanimbar-Aroe area. 19th Army headquarters was established at

Timor and Western New Guinea, This reduced the defensive area re-

sponsibilities of the 16th Army stationedin Java.

Pubicb order in the Philippines area was extremely disorderly.

Its continuance would not help the situation if the enemy began a counterattack. An Independent Garrison Unit was stationed there to take steps toward straightening out the public disorder by spring. Miscellaneous Actions During Second Stage

Order of battle; for the 3d. Air Army was issied an 10 July

attaching it to the Southern Army. This was the result of the

general reorganization.

After the Chekiang Operation on 28 July, the China Expedition-

ary Army had been ordered to take: the strategic points of Ohinhua

Vicinity. 'On 3 September, Army General Staff had ordered the China

'Expeditionary ;Army to prepare the start of the Chungking Operation

previously mentioned. Later, on 10:December, it was ordered to

suspend'the ;preparation

On 23September, the .Northern Army had been ordered to dis-

patch, temporarily, part"of its force to Central Chishima Archi--

pelago to strengthen that garrison.

-The Northern Army was ordered to secure the strategic points

in the Attu Island Vicinity, with a part of the Chishima Fortress

Tinfantry Unit on 20 October. That unit was placed under the 5th

Fleet ccmmander:

The order of battle for the Ntorth Sea Detachment was revoked

on 2LhOctober and the order of battle for the North Sea Garrison

(compo6sed mainly of the main, force of one Infantry Fortress Unit

and thre Infertry Battalions) was drawn up. The North Sea Garri-

son was"to come under the 5th. Fleet ,commander, and was to occupy

and secure the strategic points in the Aleutians.

Line of Counnication.(LoisticarSuport) fkiring First Phase

During the first stage of the First Phase, operations of the

Line of Communication were excellent and very few interruptions were

noticed. It was not: necessary for Imperial General Headquarters to

watch the transportation activities directly because things were

working out so smoothly. However, about the beginning of the second

stage of the operation, Imperial General Headquarters was compelled to take over the Line of Communication as described, previously.

As the Southeast Operation became more critical, the Line of Com- munication to and from' the Southeast Operation became practically another main role for the Army Line of Communication,

Difficulties encountered included such things as: a way to transport supplies in view of enemy air superiority; study of

special field rations; way of counteracting FMalaria; and establishment of local self-support. These were all difficult problems.

The biggest was to avoid enemy attack due to their air and sea

superiority, Such enemy interruptions made Palau a much more important intermediate supply base. Due to heavy losses encountered by our transport ships of various types, we were having difficulty in finding a way to produce enough ships to replace the losses.

During November and December of 1943, the increased requisiton for more ships began to affect the stability of the National Economy.

This also affected the capacity of the Line of Communication to the China Expeditionary Army and caused suspension of attack operations toward the interior of China,

At the close of the 1st Phase of Operations in the Southern area, we realized it was necessary to complete our supply situation for Manchuria. The necessary requirements for battle were to be stockpiled, About the end of October, the Inspectorate of Supply for the Kwantung Army was established. A Munitions Transport Con- trol Detachment was established at important harbors of Southern

Korea, Northern Kyushu, Seto Island Sea, and Hokkaido to strengthen the main transportation lines to the continent. CHAPTER, V

Second Phase of the War

(January August 19 L3)

Situation Estimate Regarding Enemy Offensive Potential

The estimate by Army General Staff of the situation at the end

of 1942 concluded that several potential enemy offensive areas ex-

isted.

In the Southeast area, it was anticipated that, the enemy plan-

ned to attack.Rabaul' since it was the operational base for our Army,

Navy and Air Forces. To accomplish this task the enemy would start in.the Solomon Islands area by trying to drive our units off

Guadalcanal Island and then advance northward, through the other

Solomon Islands. In the Eastern New Guinea area, the enemy would

secure the Buna Vicinity and attack Lae and Salamaua from the sea.

After penetrating Vitiaz Strait, they would attack Rabaul in a

joint operation coordinated with forces from the Solomon Islands.

After this, it was :estimated the enemy would attack the Philippine

Islands by using the: northern coast of New Guinea as a route of

advance.

In the area North of Australia, centering around the Ditch East

Indies, the enemy was expected to make a synchronized attack on Aroe

and Tanimbar Islands. At the same time, they probably would take

action to advance along the western coast of New Guinea to attack

and control that area.

In the India area, the enemy was expected to try immediately for recapture of Akyab and to strengthen air operations. It was anticipated that toward the end of the rainy season they would plan

to capture Burma by a coordinated attack from the east and west, with the main force of the British-India Army operating toward the

Imphal area, and the Chungking Army operating toward the Shan Sector. iEeanwhile,. the enemy was expected to attack the strategic points on Andaman Island and secure sea. superiority in the Bay of Bengal and the Andaman Sea.

Expansion of submarine operations throughout the entire South

sea, area w,,s anticipate.d,. 4Atterapts a

In the general situation of the Southeast area. (center of future operations), sea and air superiority over Guadalcanal and Southeastern -ew Guinea Islands' had been captured toward the end

of 19h2 by the enemy.- This, was due primarily to' losses suffered by our I'Tavy,' especially 'in air strength and auxiliary ships. At 'the same time, the enemy increase :n Na4~ and Air Forces had affected control of the sea and air. It ;became increasingly dif- f icult 'to send men and munitions to the various Army and Navy Units on Guadalcanal and Eastern Ne~ Guinea. Aftei mid-VDeeiber, even transportation of minimumiquantities of badly needed supplies by small .craft on moonless nights became difficult. 'The, units on Guadalcanal and Eastern New Guinea struggling against 'starvation, combat fatigue and superior enemy forces were in "a serious pre- dic3nent.

!ore' and more ships were needed due to the loniger sea supply routes, but the total number of available ships' was decreasing daily due to an unexpectedly high .ship loss.' This caused a sharp decrease in the number of~ ships to transp'ort raw' materials which were needed for the gyational iNobilizaticin Prografrn and were vital to :the basic 're auirerrients' of the nation' s fighting power.

In Europe, Germany was entering its secondwinter 6'f war a a ndnst wath sew USSRno.'ong er able to c a.rr y'6u -Its operationsagai in the Stalingr'ad' area; Ithad' turned todefensiv& tactics after discontinuing'. its offensive dri~e.' At -the same 'time, the fighting power of 'Alied Forces increased in 'both the east 'ard west of the European Theater as well as the Far East,

Faced with these facts Imperial General Headquarters concluded

it would have to abandon all thoughts of recapturing Guadalcanal

Island and postpone all immediate plans to secure Eastern New Guinea,

especially Port Moresby.

Amendments to 2erationl Plans for Southeast Area

Solomon Island Operations for the recapture of Guadalcanal

Island were to be stopped. All units there were to be evacuated

between the end of January and the beginning of February, Later,

the Solomon Islands north of New Georgia and Isabel Islands were

to be secured,

In the New Guinea area? the operational bases at Lae, Salamaua,

Madang and Wewak would be rapidly reinforced or established. Im-

portant positions in Northeast New Guinea (generally north of the

Stanley Mountain Range) were to be attacked and secured. Prepa-

rations were to be made there for future operations. According

to the situation, units in the Puna area were to withdraw to the

Salamaua area and secure necessary positions.

Under this operational plan (established 31 Dec 42), the front

line on the Guadalcanal Islands was to be withdrawn. However,

there was no change in the plan to secure a string of operational

bases connecting the important positions between the Solomon Islands

(Rabaul as the center) and. Northeast New Guinea (Lae, Salamaua,

iadang, etc as nucleus positions). The new plan was organized to

avoid a disadvantageous battle on the remote islands in view of

the trend of the war. By this new plan, the Japanese force yielded

the offensive and assumed defensive positions in the Solomons area.

It was a major turning point of the war in this area.

During the Second Phase of operations, enemy counterattacks

became increasingly active against the outer boundary of the opera-

tional areas such as the Southeast area, Burma, the Aleutian, etc. Meanwhile, the strength of the Japanese Navy and Air Force was

declining continuously. a facttrue since the outbreak of war.

This forced us to switch to defensive tactics and strengthen the

important positions captured in various 'East Asia enga eneLsts

In the Southeast area and in-the Solomon ,Islands5 plans for the recapture of Guadalcanal had been abandoned, Units on the

Island were withdrawn during the early part of February 19)43, In the New Guinea area, units in the Buna area withdrew to the

Salamaua area to prepare for a counterattack, Rabaul and other strategic points in Northeast New Guinea were to be used as operational bases. In June, the enemy landed near Rendova to attack our aifr base at IMunda, After stubborn resistance, the Japanese

Force retired to Boungainville Island.

In the New Guinea area, forces atthe important La and

Salamaua areas were withdrawn ..during mid-September since there was no hope. of maintaining those positions. The forces began to

concentrate in the Finschhafen area on the west coast of Vitiaz

Strait.

In the Burma area (Southwest Area Front) an element of the enemy in the Akyab area had planned an offensive operation to begin about the middle of January. Our Army, however, took the

initiative and upset those plans,. There was no change for the

Northern and Central part of Burma except the enemy preparations

for a general counterattack scheduled to begin at the end of the

rainy season.

In :the North-of-Australia area, there ere no immediate plans for an enemy offensive before the end. of .Auigust. However, the

enemy was interfering.with. oa defensive preparations by pushing

air and subinarine-warfare. Transportation to these isolated islands became' increasingly difficult, .; In the Northeast area, the US Army landed on. Attu Island on

12 £ay. Although our Army, and Navy units resisted stubbornly, they were annihilated by 29 nay, All units on Kiska withdrew safely to

Paramushiro on 1 August.

In South China, the China expeditionary A.iry attacked strategic points on Haikang Pen insula and entered the 7,ench Concession at

Kuangchou Pay during ,the middle part of February% Our forces had

anticipated the enemy intention to increase activitis of the ir

air force in China and to start a drive into South China with their

Chungking Army.

Orders and OperationalPrinciples for Southeast Area

Orders issued on t January to the 6th Area Army conmnander

stated:

1. Imperial General Headuarters plans to establish a

more favorable situation in the Southeast Pacific

area to carry out the war.

2. The 8th Area Army comander will occupy and secure

irportant positions on the Solomon and Bismarck

Islands in cooperation with the Navy. He will do

the same to obtain important points in New Guinea

and begin preparations for future operations in that

area.

The Army General Staff ordered the 8th Area. Army to conform

to the following Army and Navy agreement regarding the operations

in the Southeast Pacific area: the objective of the Southeast

Pacific Operations was to gain a more favorable situation in that

area; the Army and Navy would first cooperate in making coordi-

nated attacks and occupying selected important positions; in the

Solomon Islands area, those islands north of New Georgia and Isabel

Islands must be occupied; and, in the Eastern New Guinea area, important positions in WNortheastern New Guinea. must be. occupied for use in future operations, All Army and 'Navy units were to withdraw from 7uacialcanal

Isl ands between the end of January and thebemx. of February.

All available failities were to b e usedin cr -ig this.

Defense of important positions mentioned =n the preceeding paragraphs was to be strengthened: Resonsibi ltyr for this ,was to be divided between the Army and the. Navy. Th ilorthern Solomon

Islan~ds (Shortie~nd, Bougainvrille, and Buka Islands) were to be

controlled by the Army. New Georgia and Isabel Islands were to be controlled by the Navy.

In'the Guadailcanal Islands area, Navy units were to continue air wrfare and atWeipt to out off enery .supply lines in cooperation with submarine operations.

Operational bases attLae, Sal naua, !adan.g, 1eWcak, etc were to be strengthened and important positions north of the Stanley Iountain Range in Northeastern 3!ew Guinea were to be attacked and occupied.-Preparations for~ future operations, csp ecially against Port :(,orQsby,, were to be made. In the Tuna area, units were to withdraw toward Salaimaua at the proper moment to occupy vital positions.

The Army Air Force was to cooperate with units in Now Guinea in ground operations and defense, to protect ground transporta-

tion, of supplies- in °the New Guinea area, and to obtain air super-

iority- by annihilatin'g the 'enemy air force in the Eastern New

Guinea area. The latter ias to be done in close cooperation with

the. -Navy.

. .The Wavy Air Force -was to carry out air operations in the

Solomon: Islands and N64e-wdiiinea. In the - thdrawel from Guadalcanal

Islands, the Army 'randNavy Air Forces were to cooperrite in destroy-

ing the enemy air"force regar~dless of former orders. Working with the Southeast area Fleet, 8th Area Army made the necessary preparations to comply -with. these orders.

General Operational Progress During Pero.iod

Between 1 and 8 Februaryg the-'entire Army and Naval strength, consisting of -some ten thou.sand* men, withdrew. to. Bougainville

Island by destroyer. The evacuation required-'three separate trips, each under extrenmely hazardous conditions.

Previously, on 5 January, the 8th Area A ry commaander had tranr porte an element of the 18th Army (part of the'51st Division) from Rabaul _to Lae to attack important points in the Lae and

Salarnquaarea. :This unit landed an±d attacked the enemy at Wau but the attack failed due to lack ofnMand munitions. The comm-finder realized it was im ertive to reinforce the LLee area. To fulfill the requirement, he committed 18th Army headquarters 'and the main body of the Slat i vision which had..been located at Rabaul. In transit, on 3 March, this group was attacked by approxsimtely 130 enemy' fighter planes and bombers at Vitiaz Straits.. There, the majority of the convoy ships were ' sunk. After this, it was impossible to send men and munitions to- the Lae area by surface transport. They had':to land at either the rear bases in Rnsa

Bay or near Wewak. Then they advanced to the front line area by either march on foot or small bdats' even though interference by enemy airplanes, torpedo boats and.:the lack of roads'in the un- civilized areas made . it difficult.

Units in, the Puna area withdrew by.. sea and land to Salainaua simultaneously with units from. Guadalcanal ,Island. _Suring mid-

Parch,M the,.2d Division which: had, suffered heavily from operations on Guad.lcanal Isl and was ordered.to withdraw to the Philippines

to reorganize. '

During the first part.:of April, elements 'of air forces from each area were dispatched to. the Southeast area in an effort to strengthen the ceombat capacity of the 6th Ai r Division.

In June; ° the army made plans to capture the enemy air buse which was under construc tion at Beni- ena, Eastern yezw Guinea.

To- carry out this -operation. it, was- necessary to, fur'ther. strengthen

heair force.- Accor dingly, the rn-?in force, of the 7th ir Divi- sion (previously stationed in the. North-of-xlustralia are,,)) nd the; 1st Raiding Brigade (a paratroop unit. stationed in Japan

Proper) were dispatchedto the Southe ast ar a.

In lato July, the bthAit Army headquarters was c xgni ed to

strengthen the air gommiand structure -in thy; .Southeast area. Thi3s he,idqiurters was establ ished. tQ be in charge' of. the 6th and 7th

Air Divisilons and operated unider control of the 8th Area Army con- manler,

In the Solomon I slo:nds : -rea, the.- rn my 'l. nded nr Rendov^.

(Central part of the olomion Isl .inds)} to ad the end of June and

attacked. !aundar-~field. In the :some area; Army and Navy Units

(with th;3outh ^ast Detachnenit as nucleus) f oug ht. bravely but due to inadeqixte stre ngth were defeated and forced .to adopt guerrilla :Qperations. They vRithdrew. toa ouaainville Island from ColombangUara. Ard Vella Lavella::Island toward: the. erM of .September.

-If :our forces were to attack'-enra Bena inwthe lew Guinea area, .according- to. the ;basic' plan, the 18th . Arny coimmander considered the attack would not be, >s ucersful :because of 'enen.r air.-superiority .It woul.d be iinpossible to hold :this area after ground forces made- an~ attack.- 8th .Area Arr and .the'..army Genera:l Staff acknowledged thi.s, As a resul.t, the., attack' was not car.riied out. Since unite at Le e and :Selaiaua. seemaed :to 'be 'unable to hold- their positions, they were ordered to withdraw toward;~ the Fihschh.f en area,

:vest of Vitiaz Strait .at .the -er " of August. Thee Ni Guinea force was .also ordered to strengthen: the defense ^f Iadang area. Important positions in orthest' New Guinea area and near

Rabaul were' located ideally to serve as interrelated 6oezrational bases which would 'allow us to make full use of Navy and, Air fighting 'power in the defense line. Although theArmy and "the La ry did their best to hold these positions, 'the strategic point .s along the front lines gradually fell into eneyv hands. Tho general situation for the Southeast area became critica~l hen it appreared that Rabaul would be isolated as a result of th'e heavy, reinf rce~- meat of enemy air bases at Lae and Salai haua.

Central Pacific Area Onerat ions .When the situation in the Southeast area turned for the worse, there was an. increased possibility of an enemy attack on .the isolated islands in thQ Central Pacific area, such as the Gilberts, M1arshalls, l arcus, etc. The Army dispatched troops to the following places to reinforce Nahvy maintained defenses. The 1st South Sea, Garrison Unit for' the Gilbert Islands and the. 2d South Sea Garrison Unit for Miarcus

Island were sent. by orders issued inn.nmid- Aril. The 3d South Sea

Grrison Unit for Wake Island end, the hth South Sea Garrison TLnit for the Gilbert. Islands were sent .by orders issued in mid-Juno. Units at Marcus Island were under the command of the Yokosuka Naval District,

Other unit. in the., Gilberts were under the _uth Fleet cornander, On 17 July, the destination cf the 4th South Sea Garrison Unit was changed to Bougainville, Island while en route to the Gilbert Islands beoauiso. of the war situation which required additio-nal troops for the defense of Bougainville in the action progress ing there. Orders and 'pr ational IPri nc : ale s or Southwest A-,rea

Toward the end- of -Fehruary 19.i.3, the' Army ! neraJ Staf f decided upon an Armny oper :ticn plan for the Sri?'thwset a:e to be used during' the year. It'~ provided that.. I m-orbant positions. in the southwest, area were to be se cured in cooi:)e4 ationrtwith the ta vy.. CoLLec- tiorn of intelligence inf ormmation was to be stressed. Strengthening of military :preparedness was vital in this area. If the oenurr attacked, the A r, Navy! and Air Forces were to concentrate teir fighting power wherever necessary to destroy the enemy and. their fighting morale,* If the general sittn^ tion were favorable, ground operations against Ntortheastern. India were. to b e carried out, Main efforts f or operations and defense woire to be' cencertrst d on Burxr, and important natural resources areas, Public order was to bfe~ en~ forced in the Phlipines.' To accouplish the objectives of the operat ionsl pla=n, areas occupied currently in the 2Southwest area were to be maintained end safe-guarded', In Burma, the Tenasseirim a rea and the-- area from 'he

Salveen River, and to a line on 'the we st.linki ng I rytkina $Kaa ing klewa, Gangaw and Akyah were to be secured. Battle prep rodnuss should be strengthened, inm ediatoly, in' the sectors having sea supply routes where ceno; iy lanes could attack (Burmia and Banda Sea areas), als, .,the Pa"! qnbn and 'the Pangkalan-E3randan areas-.were to be stren gthenced, Irn 'i tel..

COune ratt Ck o r .,ione int he JMq),b areaJrovided tha c n~b Y'unhits atta cking along th :AkyaI:)front wret c15e dos-ro ed.. bky a4frc organised from e le ment s of the 5th. D.ision. This unit was to :procoed toward the Buthidaung. and.Kaungdaw Lines. To assure the security -of' Ayab, ground supply routes were tobho e stablis1 ed. lso, protectior of sa , supply routes was *tobe increased, The :fortifications in the area w.ere 'to be 'stron tihon od and work on -air bases c onrpetod .

8h Our counto raattack op ration ~gainst 'the anticipated mairn enemy

,tattack in th, Burma aea called.Yfor a s tronp element of forces to

secure important lines along~ the bdrder area. The main 'forces wero to conentra to at the handaClay and T6Lingoo Road aroa md take tho

offe;nsive at necessaryT ooints bTr rabid moements dosignad to achiovo the separate do struction of 'the Chunigkcin -^and British Indian Armies.,

It was considered e~p'ecially important to carry out -a major decisive battle with the Brti.sh India .. trmsr and 'to ennihiliato 'it in the

defle of the Arak n houitain R ,rgo . To execute this operation,

special attention had to be paid- to tho -com pletion of transportation

faiJitios, fortifications and° safe -guarding of , mporta.nt' commni-

cat.ion points. This 'opeirationas xpected',to toI place after.

the start of tv- dry soason. Total i itay 'streng'th scheduled to

participate in tb Burmla Oera~ions was to be about six or seven division s,

After the rainy seas on., if conditions we r favorably , a ground

offensive was to bu- la unched a ainst the' Tinsuk is area, northeast

of India~ Objective of this ';wats to cut off ai.r transport (Flying the H mp) reinforcemh nt of the Ch ungii Army.

Tn th e f ield of air operations, beoforo 'the start of t'e ri ny

see son, an el. ent of the air force Z'8s to carry out 'surpris tak

against the ono.-Vy air force 'surrou~nding Burma at opportunePr moments

and make every effort to mi-niumize -losses. This zwas to be an effort

to eliminaate enemy {air superiority o e r Burl a At the same time the a r fora: was to cooperate with offense re operations ' in the

Akyab area,

i:.trthe ra1c ya u n ythe%;main f orceofthe eAi ry was to destroy the enemy air:forc ' in East India 'and check ~future

reinforcemaonts Vhonever the enemy -took the. ground offensive, the main force of the Air Army was to cooper ate ''77ill"the '15 t Army. EEVery o..:ffort Twas to 1bemadV-Q to . .. l l.r. L2: 1-.:it. bV. p at rols and equip .intelligence units ;adc qutely 'to pr~ovide foil irfo_.ration 'gardinc ,ene my Jntuntions. If t:i.._n_, my m 4iov S to.. Ottrnok, they wore to be d stroy ,d by our irt d vUr, :o rces bf ors they could. land..Ax'rbases were. to be ouippoe d.,^s comrIteya

Bible to support th s operation.. Indoendeib. rrison . it, wore to :dofend sectors: in which possible of or y ler-ziig s w 'e .antio a ted and wore 'to :fortify these vita).- positions, * txat egicaillo c?'ed. mobile divisions weQto ;bemoed .inra .dlys .reinfoarce rent, ,:": wh'ioe needF d, to crush y r. enemyT landings.

A~von .ftho situctjon °tux'nl.d for the -rdrse , emazgrdu.ps.o.. of sir b4 ses, :.onexationalhS , etc w o; to be -held .and- de volopebd-

to'~aolitteair- operations and future,onsive,opq t.ns All transportation faciliies were to-b: ut li 5 insenrding ecessvry.

reinf~omnt oke'araIt was of t. for rrtceht mi

coinuni.cation lines b roec dfrm fl2iy .irand"n"aal Cattacks.

Operations .for Mai y , S3aatra rand J vt , called fox' our f orces

tbe prepared to c, in.ba.''t eno:.attcs.Sreil mhai wsto

bepacdnte defeonse.y of the' Cm~an '''1ae. 4n..,,-1y ;)Pl.ans must:

bintercepted and cl darlrinterpreted., Thir aircraft carriers

.and a ir bases were to be destroyed .before a n offensive. opo- _tioxCs by the enMy could be mflonted . Thae Jap rose 2rrnyndNay i

Forces wreto aco. pl4 sh that. Allf. figh to.--p }ane :units wr oeto be deployed-.to repol any eanemy. air attacks*

in other aes, sp ec.aIlly Ml y_nd th Philippnin Isl ands, mopping-up operations vero to be spoedod up " in dqfonse . obcratio 's for N1-orth -$'ronch Indo--China, f the C ungking IArmy moved- to attack,

offers iVe:. actio tin~ to be toakfon in the important border ar as and1 the onemy.;tas to be destroyed.- Our forces were to haT eccopera tion of the French. Indo..Gb n aArmy 9

ozI6 Troop Activities in Southwest A1rea Oprations.

The 54th Division was sent to Java- from the Hiomland in Narch and pl2 cod under the c ommand of the 16th Armyt.

At the end of M~arch , as operational conditions in: the Burn .

During thze middle of bruar"y, the th Division took .the offensives de:.feated the. e¢nem. y and.. Iccupied theBu ihidaung area. Theenemy plan to r cature ."iky b, during the dry sea.son was unsuccessful.. There were .no groat changes in the cetral 2nd .Northern are as of Bumexcept .for enemy ~ccounto r ttaoirp Prat onsl. This was expocted to begin at the start 'of t ~yseason. 19th Army r adqu arters was orgmi_.zcd ~ placed under. corn-. mind of South ern Army G noral headqurters on 7 January when it became nocossaryrto strengthen mlit -ry p rae nosy or the North-. of -Austrlia area, This was cautsed b.y the change in the war. situation in the Southeast area at the beginninpg of 19.3, 19th a~rmy headquarters toot charge of :various units:..mostly from the

5th and h8th Division. On 30 January, the 7th Air D vi.sion headquarters was org nised and placed under commandcf -the 3d =irA 'rmy, It c ominande d the 3d Ai Brig ade, and nth_ r uit s and was responsible for defense of. the

North-of,.Lstra1i tar %'4 In .that are a, there werk no, indications of active enemy plans before the end of August * Then, influenced by the strengthening of our milita ry forces and. ipositi -ns, thewr began tak~ing. pro c utidis g:inst ptnti 1 offensive plans of ours.

The. enemy bqg^:n to ups -t our. plans by, cutting off sea transportation, causing dif'ficu lty in supply and porsonn 1l movi.rmnts to isolacted islands.

In Southwest ,n hina±, enem7 act'i.i cs ,e o quiet alt o-ugh

thern wern indi cations th"ey izcr; aa.i.n "t.tosynca etr-ngrc

to Burma 'nd Yunn a4reas £re.r6 'Th~oCh' . gk .LaTand.Ch an csha a0re as. It the :.nd of August, the 54th Dig% ign wae v&t um ce o peraicmns in -ur Java,aw sin re to ata 't at.: .:.th o,b eg L inr i;from in

Of the dry se.ason.

Troo:p Aciir.tts n ther Areas At the end of L 9t2, the 1st ir Division -wnd r the&coadof

the 1st nrAmyh be r, 'edtoteghe i.r~a~ns

ryhAthe ioxt heas, ra During the :arlye port of F.'e ru4.f.y" it was Placed under control of*era theNrt .J.,. WorCLJLth 6t . e, Armyt..,i. }S d 'i2.so' 1 in th '?erthewstYc! area blir-,.ring tha t the rocapture f .-to and

Kiska Islonds by thAn p~~ rd cate;d -lans for increased activities iithat area. On 20 Na y the 7th Division wavs placed tnder "corrfland oif the North :Lrea -- J. core ard r, On 24 May,^1Hokk'id was placed of war tiro defense. In 2\Ausut, the 3d and t e 4th I aril. Islands Garrison Units wore placed under com iand of t ho Nocrth Area, " rmzy commander an riddeilc Td 'inithe Kurile Isl:ands.

Inh wrench Indo-China, enelmly ir. raids frmm Ch i m bas i-ncre:asedl and an advance by the Chu gkin :Arrfj a^gains t French Indo-China ;Tras c c ct d. About .the mriddle of January, the _-rr yGeneral Staff decided to. sol idify control of " rench 'Indo-Chia '. t th ; end' of

January, orders -tore issued for "the~ attack and capture of important points!'mr Haikang Peninsula. Aliso, the French Cncssioriiin Kuaigchoui .. w stobe occupie;d. Thoe acti',.)Xs we re aeeonlished .in iiid Fob ruary by the Chita a _ ditieinary irmy.

At the. end oJ. Februc'ryr t h hna Lxechtionary 1Army was :ordered to destroy enemy.. p_.ans .to c ontinu comibat and to check activities

88, of' the enemy air forces.

In M~arch, the 61st Division was dispatched from Japan Proper to central China and placed under command of' the 13th frmy. In

Juno., tho 17th Division was as sembled? at Shamnchai. to prepare for shipment to the Southeast aria.

In the ±lachuria area aout the middlec of June, the 27th Djijr sign was transferred from 1Nrth Chinra and olaced under coyma~ncl of the Kwrantuang Ar y.

Line of obmmunicaton (Io isic .. Support) hixirigS.cone} Phse

In this' phase of the war, it be came; ic fficult t o r^nago the Line of C ommunia tion because of the unfavorable turn in operations and the increase in ship l osses.

In the Southeast area, units were ithdrawn from Guadalcanal

Island, Burma and &uncla island etc, because of shipping supply dii'.- ficultios. Our f orce s triedl to transp ort supplies by establishing land rou.te s and by using small landing craft fCor supply. Landing, craft for this purposeere fitted with fire arms so as to fight enemy torpedo boats. If Rabaul, which was this most important ba~se in the Southeast area, should be isolated it would be necessary to support the fighting strength by a system of self-sufficioncy., The Army decided to stockpile opera:tional material imnmeditely in

Rabaul. The Army put this plan into. effect from the end of Bur st

19h3 to the middle of V sembuer. The plan far the most part was successful. Because of the serious situation in the Southeast area, it becamue necessary to strengthen military preparedness in the Western New Guinea and Moluccas areas. The Army Generral Staff ordered the Southern Army to establish a base in the Halmahera area.

At that time, the various plans of' the Southern Army relative to thei Lines of' Communication and especially the system of self- sufficiency were progressing smoothly. With the development of the c r i t i ct alt w a r. ns 3i t uu o t i o na i nu . t h 3e o fu~ t h- o a rt o ra r ' ' a nd a pbs" i t.ut b c m o d i f sary to n ctd ham ,rora the. S uthw s aroato0 try : bdhbest ar n to ostabl.ish a spacial. transportst.Icn routo for this } ur>>so.* Tho sh il i~no Islands becamne o;n moro- -ia~s an .t;int.ndaQ base between th~e Southwwst area ard: So uihoas:"t .reaSh .ps from Japan Proper which were to o to the Southo ast gry "Iria. alau w, oe ordered to use the Ph1i ippin es hs'rbors ns rolayr i-zatp.

90 CHAPTER VI

Third Phase of the War (September 1943 - June 1944)

PAT T First Stage (September 1943 February .11.)

Situation Review and. Estimate of 'Potential nem 'Plans

During the month of September 19h~3, considerable activity took place in connection with the war. On 8 September, Italy capitulated, breaking the Tri-Partite Alliance provisions. oith development of the critical situation in the Southeast, the shipping losses, aircraft losses, etc, a comnplete review of the total war picture was made by Imperial General Headquarters-and a revised operational plan drawn up, All matters affecting the war were discussed and. the final plans were approved through a Council in the Presence of the Emperor on 30 September. General details regarding adjustments in military and governmental policies are included in the following text.

The enemy situation, as interpreted by Inrperial General Head- quarters in September 19 3, concluded that prospective enemy counterattacks would be extremely severe. In the long run, it was estimated that attacks by Allied Forces would be launched against the Axis countries and their satellites. Between the latter part of 19:3 and spring and summer of the following year, it was believed the attacks would reach their peak. In the Far East, Britain and the

United States would increase pressure on Japan in cooperation with

India, Australia and China. Sharp counterattacks were exnected in the Southeast. Pressure would be applied at the.same time against our Southwest and ortheast areas. Our important occupied areas would be subjected to intensified eneiy air and nay. attacks. Enemy planning, apparently, was designed.to terminate the war in the Par

East as quickly as possible.

The Nationalist Army in China, most likely, would continue its fight against us. Activities of Chins,-based enemy air forces would be intensified. The chances :p;f, aet-~n.wax with .Russia .conrtiniued favorable. At the same time,. the. possibilty.t th TiUnited : tates would be pz'ovided air base facilities iii astenh.ssia couuld. not be overlooked,

Thx e m Ant e gl y o- 2Am 5er 0 ican pl nfron s a t dline ap r forx ce m twpas r l y co 23) np o se d7 iof o s(Sei. 1c 0 ing the strength of its reserves, it was estimated the air force had approximately 6,000 planes and ground force strengtah of from

70 to 80 divi.sions. ...

Estimated isnosition f Enemay Air and Ground 'Forces

* Air F cr e Strength Ground :Fce Strength Area('T fPae)(of

Frontlinere Ftrlint

Northeastern Approx A r. r(ra I . r larea 300 ~ 8 00 2 to 3 f6

Pacific area 1 200 .1 .000,1

Southeastern Approx Approx pr j 1r

area 1,300. V 3,Qjr . 0 . 33

Southwestern ,A+ rox Aprcx A.pkpro:ar n Prox 1AParea.6o0.1:000 10 3

E~nemr reinforcements in the Pacfic Theter would depend. .

largely on the degree to which the .en riy epected to. establish: and maintain a second. front in Europe. Also influ ncing this would be. the enemy shipping situation and the degree of progress in the

various phases of their .preparatio~s ;.for' battil... *!Ls of Septemrber

19.3,, the enemy. ww expected to continue concent'cting. oni. the.. European Theater.

92 ,.oof ~rEne.t..y .T..hea ter... ,Strengt h ,ected 'tmt ww....Es - - - Pro .M..,..w- im te Pacific

A .r Force Strength .. Groyne? Force Strength Period NY~o of Planes). QNh of Divisions)

Fontline To t aFotiroa Frotli e 1Stnth-Streng]th

End of 1....3 1ApoxAloxAp Li,000 7, 700 35 90 to 100

Tuli.ddle of Apo Approx ApproxH 1 -100 to 110 19144 f ,300 9,00 43

End of 19144} Approx Approx ,:,pprox l0 to 120 :7,000. 12, 000 60

The *main force of the United States Navy was operating in the area between Hawaii -and the Southeast Pacific area, It was divided into several N~aval Task Forces. Total strength of the main enemy force included sppro imately 6 ,aircraft carrierss, 15 'battleships and

15 cruisers. Besides, these, there were iall task-force type units in the Alaska-Aleutian area and ir the vicinity of Australia. asp proximately 10 converted aircraft' carriers were performing the duty. of escorts as their principal task.

KIt was estimated that the United States ' ould have ,12 carriers on hand at the end of 19143, and thi~ was 'epected Ito .inorease to

16 in the middle of 1914h and to 18 at end of 19th.. Since America'ts ship building was moving along veil smoothly, there could be cquite an increase in the number of, snips. The, enemy' s excess shipping tor nage amount~ed to 2,000,000toe The annual increase in shipping tonnhage was est mated to be in the vi cinity of L,0Oo)0 to 5,000,000 tons.

The British Navy in the Western Indian Ocean was, comRposed of 1 carrier, 2 converted aircraft carrlors, 4 battleships and 10 cruisers as its main strength, Since Italy :gad capitulated,' the possibility of a timely re nfo O~inrt oc this force by 4ior5 car-

riers, a few converted' carriers,;, ?Jor 3 battleships and 10 cruisers

from the European Theater was:, expected. Hawaii, Dutch Harbor (Aleutian); Brisbane and Perth (Aultra ia~

were being used as, bases for approx. '06l American submarines.

.bout 10 British submarirnes were located, an the Ceylon area with Ceylon as the base.

Beginning about the end of 14h1 a .d extendineg into 191.L, it was

estimated the enemy would plan to conduct coribined attacks fromr the

. east and west in the Pacific area and cap'ture strategic points such

as Rabaul in the Southeastern area and 'Bura, Andamian, T. icobar and Su-

*matra. in the Southwestern area, As part of' the ovrer-all ,.Rabaul a ea

operatioias, following capture of Rabaul the enemy would direct assaults against the. South Pacific ii:andated. islands and the Philippines area,

As of September 19. , it was believed that. t e enemy had intentions of launching attacks against:the. Kurile and Banda Sea areas,

of repeatedly bombing Japan and. our occupied positions, and of in-

creasing their attacks against our shipping. Probability of large scale enemy assaults, considering their current available carrier

force strength, against the Central Pacific Islands was considered

unlikely. However, toward. the end. of the year,. enemy attacks in the Gilbert And- Nauru .areas or in the Wake and Marcus Islands areas in

conjunction .with attacks in the. Rabaul area were quite probable. Army General. Staff Opaerationial Plan Changes After reviewing and studying. the various situations, the Army

General Staff considered it necessary to alter its. operational plan. This was done on 15S eptember. The A-Pii'was to cooperate closely with the Navy. and .direct the

operations according to the following. plan, 1.From our~ positions in the Soi.4thestern area, we would

Strive to destroy the approraching. enemy. Our plan would

be to carry on a strong delaying action, Du~ring this time, we would complete the construction of defernses,

extending from the Banda Sea area to the Caroline s3.n.^.

and increase our cournterttacking strength. Powrful

attacks were to b : thrown ag^.inst the enemy, and their

military intentions were to be anticipated snr' crushed

beforehand.

2. Our posi.tions in the Southwestern area were to be held.

firmly. For this purpose, the complete destruction of

any advancing enemy in the Burma, Adaman, Nicobar and

Simatra areas was essential.

3. Wihile maintaining our positions in China, we would increase

our pressure against the enemy and destroy their will.to

fight. In the north, preparations for battle would be ex-.

handed extensively as a threat against any Russian' idea

of granting air base privileges to the United States.,

Also steps would be taken against the United States, sea

aid route.' The Russo-US relationship was to be played

down and steps taken to prevent any joint overt action.

;ar with Russia was to be avoided..

Defenses of our Homeland, oil regidns of the'Southwes't

ara and 'naritime shipping routes were to be strength-

ered to assure a satisfactory execution of our opera-

tional plan.

t ie would make destructive attacks' by using raiding

tactis .deep behind enemy lines extending through

nunerous 'areas,

6, Every effortwould be made to carry out operations using

all' available forces in combined efforts, including

the Arnmr, avy and Air Forces strength plus surface

transportation facilities. The above-metioneFd :la. was necessitated by the foreseeable loss of the done' including eastern N!'w Guinea : Also, in spite of tremendous effort to hold it' as a security line, loss of the ' Morth- ern Solomon Islands in the Southeastern area w sexpected, Finally, the unfavorable trend of the war in the Souttheao beun Region~ of which Rabaul w,cs the central point, would weaker o r pos it .on in the Marshall and Gilbert ara. Realizing thie uncetaityr of hoild- ing these areas f or a lengthey period, the defer~s e ere was

contracted to a' line extending from the Banda Sea aea' to the Wes-t and East Caroline Islands and. Mariana Islands 4 The line was to be defended using all, strength pussi.bie~ Strong h for effective tounrs:t~. attacks, especially 'that of the air force, was to be deployed, The aims of these actions were to destroy the 'enemy completely.'The w-, plan in the Southeastern ar~ea was °designed as a delaying action.

Following decision on this new operational. plan, a Council iii the Presence of, the Emperor. was held on 30 September 19ij3~ T e operational' concept of Impcxial General Headq'uarters wras approved with emphasis on the importance of its successful accomnplishraent,.

Nilitary operatiors re to be as already discussedb Special emphasis was to be placed on a rapid Increase in plane prod tc $ion,

It was also, deceded to move for meditation between Ge i.da ' n Russ-1-

to bring peace.' At the same time, ties with GF';many would be

gghtened within limits which would avoid provoking Rusaia,

BxitingInternational and War Conditions

.1t was believed. the American Army completed its base in the vicinity ofI iunda (Solomon Islands, area) during Septernb~ 1943., In

the latter part of 0ctobor the e ne ry.. landed iii the v. iyof Mon Island (off Boug .invlle. Island), The, vi:cinitys cf Fnsc.hhaf en on

the western bank f-V itaz Strait (Ne~w Guinea aroa) wts invaded i4~ the latter' part of Sept embpr , At about this tm air and naval

rperations of both sidles reached a climaactic stage throughiout the

96 Southeastern area. In. ground. actions, thie enemry, met our 17th Army on 1 November when they landed inthe vicinity of. Torokina (Eouga in- . yuile Island). At about this time, the naval .:battle. off the shores

of Bougainville had begun, During the period between .5 November and

3 December, a navA. surfface battle,. and five great aerial ,Battl.es

were fought in the vicinity of Bougainvile Inland. Be~tween mid- December and late Dec ember,,, the enemy made landings in. the vicinity

of Cape Markus and Ttuirvu (New Britain sland). On. 21 November, the

enemy attacked M'akin and Tarawa (:ilbert Islands ). .and bar 25 Nov ember annihilated our naval, land, units there. On I. Febr'uary 191h they attacked Kwajalein, anid ~o . (M'arshall Group) and destroyed our'naval

land units by the 6tlW, On 17:.. Febrary 9t 4, an eneay carrier. task

force struck at Truk and attack d.our ships anchored, there.,, Our

losses were quite .heav-y'. The :~Nagy became exceedingly aptive, and the situation in the Oentral PacificG area to"-ked very serious.

On 29 February, the enemy landed on the Admiralties.,

The enemy ,in the Buthidaung and 2.".aungdaw areas.-,of the .sout~h. western. coastal area of: Burp a,"wa. active In offense... Our 55th Divi- sion mounted a counterattack but *as forced back to. the :defensive,. Since the beginning of. February, a newly, activated .Chinese aationa,1

ist 1st Army,, having .advanced from the Assam-ar'ea to'Iiukaw Valley,l

w'as battlin& our 18th Division.t.

There were no chan es in regard to batt .e.. ituationis in: other areas. The numnerous penetrations made by the enegr in the different sectors off the Southeasten area had c u ed 6perations of the 8th Area Army to be ineffective,, With the decline of naval stten th and the state of our amyj operations, future camrpaign planning fqr this

area app eared useless in re.ieving the difficult situation facig us.

On 8 September .1943.~ Italy had surrendere , The capitulation greatly affected the European situatio.n. From November through

December, the U r~ted States, Britain, Rusa and China held the Cairo Conf c~'ence and the T eheran 'Conferen~ce. In the Far Last, from September through October', the following political agreements were concluded; the signing of the Burma-Japan Alliance Pact; the iDc a- ration of independence of, the Philippine Republic; signing of the Philippine-Japan Alliance' Pact; establishment of a. provisional government for Free India1 ; and, the s igniung of the China-Japan

Alliance Pact'.'Withi n our Homeland, the M~inistry of Mnitions was established in Sept embr, and General Tojo and Admnira .. S1'im da werae appointed as Chiefs of Army and Nay ueneral Staff' respectively, in February .194 4, Southeastern, North--of-Astralia and Centsral P~icAresO t n Strategy As a result of a Central A r emnt of imperial Gen :ral h ead- quarters ,. the Army General Staff in accordance with the new op erational plan fulfilled its responsibiliy by issuing necessary orders to the Southern Army and 8th Are;a Ar±ir commanders Qn .30 September for future operational. guiidanee,

The plan for operations in the Central and South Pacific -'reas called for a prolonged tactical.-war in the important regions of the

Southeastern area. and to, comple~te fortification of: positions for counterattacks in the area .extending from the North--of -Australia area to the Central Pacific area. At the same time, units !were to check any enemy intention of launching 'an offensive in 'the area.

1.'Thi.s Free India Provisional govern~ment was an .opportune organization with posibilitie .'of furthering the advancement of the Co-Prosperity Spherea Chandra Bohs e, a le.ader in the India Indepen- dence movement, cane to -.To k ,o from Berlin- in hav. .1.3. H'eearnestly requested the Japanese government to support his Indepe ndence movement and his plan to establish a' provisional government for Free India. Upon getting support from the Japanese goyernm ant he flew to Malay and. established his government- on' 21 October 1943. This was recognized by the Japanese two days later. Purpose, of the. EBohse governmnent was to encourage anti- it ishy rnctients'in India and to establish the independence of India. As the result of Japanese support in his end objectivs; hisforces ."coop rat ed w ith the Japanese forces in the Burmna Malay Theater. It was his influ~ence with the Indians and tike Free India .NatiofillArmy- which wa s mande use of by the 'Japanese to make their 3porations easier,.

98' The 8th Area Army commander was to. coop( r te with the.NVand z crush. the advancing. enemy i~n important sectors. ,of'the Southeastern' arc-a., This would make an off ective delaying .action oynid our vr-al operations would .be helped considerably, The Southrn A4r boiroimm.nder was to cooperate with the Na.vy in expanding pr :paration s for' covnter- attacks in the North-of -Australia ~a Objectives for each, responsibl : Army commnander were Pointed out to him on tie same day as the central Ag reeme-nt was con .tdod which included' the .previously outlined facts.

The general over-~all objectives of the plan included ' four' diits

.. The enemy advancing through t' .. £ront eob!1n :ng f ron.

Eastern New ;guinea to .the northern ,dart of t'e Solomon islands in the Southeas-tcrn area was to be crushed, and an all~-out delaying action was to be carried. outs.

2B y about spring of 194, defenses for the operational

bases in imrportant r rgioris ;extending t hr oug the North-of-Australi~a are a and the Caroline and Mariana

Islands were to bet strengthened, Operational bases in. the Phil)i nes aria,, were to be constructed.

Preparations by the. Ar'm :and, Navy of air,. ground and surface forces fqr.couintex'attacks were to be speeded up.

3.Bases in the a overretioned zones were to be used as

f ortifiled prisitions in coordinated count-,rattacks~ by forces from the various branches of- service' in order~

to defeat any offensives lautnched by the ever on its

principal Fro~ts. 1,e would ma k 0ev er'-eff ort to

attack th nmy in .advance to prevent the 'e e r fIrom= conducting -,o&ntrattecks,

hIf the o -al iuto pr twan iof'fensive operation was to be lanched from the 'Northmaof-.Austra.lja .area after the middle of 1944. As, to the direction of

such an offensive,' special studies were to be :made and

the not essary' ~rprations dr raed fors~

In the North-of-Austfa'la areas about spr n of l9hh, the army

'andl.:ay were to'" cooperate in ei 'diting'pr paratidri .of operational. bases, strengthening of defensoes, stockpili.ng of war supplies, in- cresasiig' the shipping and cohstr .ting a line ' of communication. These' preparations were to be carried 'ot 'along" with defy nsive action. ini the area. Urgency in 'com iet ig rparations as fast as possiklie was emphasized by the' war' siit.ti~o in the Southeastern area,.

In the Central Pacific area, about spring of 1944h, the Nary was. to sppe'a U~p operational preparetigrns 'on 'the Caroline id : rio~na

Islands* Necessary Armyr units' were to be dispatched .lone-& with part of a' line of -communication unit to the' Central P o iscarea, They'"were 'to coperate with the Navy in cxpedit ng' these operational preparations. They were to be placed under Thavy officers,

Arm ~yGeneral Staff directives were issucd to Army command ers concerned covering orders and the Central AJ'reemeilt? Principles in these directa'es were to be followed exactly in expediting the operational' preparation. Cpr.in.' neaaii a to be approximn- ately temp] cd' Vr about spri ng of 19U4. Thy; Entire' project' was to be' completed by 'the m'idile of 1944h. A 'few of the ess'ntial matte.rs that' had to be carried out' .for the operational preparation were; construction of air oases, deploy- ment of' essential troops, increase of reconnaissance and patrolling against the enemy,- constr'uction' of fortifications, stocking of munitions, establishment of shipping bases and, small boat transportation routes along 'the coast, 'installation of' communiation apparatus and a goeral bolstering of the system for self-subs ist- ence at Occupied pc itions,

100 Al~ooation on areas -Of responsibiit~y. for the supply system provided that Hamahera. would serve as~ the intermediate supply base

for t he Banda ,Sea area and: northwestern .dw Guinea. The terminal

paorts for supplies From the 1oinelan~d and..-the southern ;A.rmy would

be ~$oro;z for, the Ba ida ,Sea area.; Manokwar , for nox hwestern, New

* vine aad, Macassar fQr the ,Flores, Sea.: area,

To., :trengthxen dsfer s ,s of the Central.; Pacificea.Imperial

General Headquat ers senat the 52d Diyis±9 n carom Japan to, Truk in

::Vhe .latter part, of October 19hi3. On 16 WNovrmber, .the .1.t.Aphibious Brigade an4 the 1st through the 5th South Pac .fi:cfDetachm~ents were

placed under the 4th Fleet comander. The 6th Sout~h ?P.o~fie YUetach

ment was .placed; uider the 8th Area Army commander. These units were

deployed throughout the various islands in ,the C.entralJ;Pacific area,

The 25th Division was sent to. Saipan from Manchuria :.in ear1y. .Februiary 1944,

Until early Febr uary 3,944 'progress. of defensive preparations in the South. Pacific, area. indicated they. were ,reaching approximate completion.. However', isolation of the 8th, Area. Arry and. fall of the

Gilbert lands contributed to a speedup of the: inevitable en~

operations .2It ;became necessary to huZ'ry:.the txengthenf~ng of. our

defens es. During: the latter part of February,. the~3lst .,Army re«-

ceived battl.e orders~ and was attached .to. the lial.r, £fr :J9 nt opera"- tions,

Outline of the. Order of Battl~e for the 31st Army

31st .Armyr headqjuarters 29th Diviin 52d Division 1st Amphibious Brigade

Sout~h Pacific, Detachments (1st., 2d, 3d, ttn 5th) South ?acifjeo G iax onUits (2d and 3d)

Chichijimia FortresUnit

101 5th Independent nixed Regiment

Expeditionary Detachm ents (lst, 2d, 3d, 4~th,' 5th, 6th, 'nth, and 8th) Note; The 1st; through 8th Expeditionary Detrachmcnts were units urgently r xganized and transferred from 'Manchl11ria and Kra Each was composed of 3,: to 6 infantry battalions, on~e artillery battalion, one enginieer~ company arnd service units.~

y-N'r 'vY 'Central Agre:emenit Regarding Central Pacific Operations

Objectives were to defeat the advancing enerI r, secure the ian- portsnt zones in the Central,' Pacific area an~d crush enemy operations in the Area.

ry the grid of spring 194, the Navy was to ruish completion of operational preparationls in the' Caro ine, rariasa and Oga sawara

sectors>'The Armyr was to cooerate with the 1avy in preparing for~ and. harrying out ground operations by sending rnecess ary units to the Central Pacific area .a d .plyc ng then under command of ap propriate Navy officers,.

The 31st A r .c xn'tnd-r w .. s to be placed und,_r the Centr=al

Pacific Area. Fleet comnmander nand take charge of ground operations, throug tout the central aid -;-estern p arts. of the Caroline and Mariana Islands and in th >O;asawarn sector. Regarding grcunzdopzratio.ns on the various isl1 nds; the respective local; senior army cornmnd ers were to assumie.conand of. all, Army units (excludinig air atnd .,air defense units) on the .. l rds: Involved disciussior1s, were held before a final decision, was,; reached on: the Cen~tral. Agrteoment. W~hile preparations were .being made to issue orders for the 31st .Army according to the tentative- agreemnent on unified operations under command of the Natvy, the Navy requested (in mid -February) that the ar'my strength in the .Central

Pacific area be kQpt separate and. that the operat o~zs. be carried out by normal gQop erative methods, betweeri Auy, and Navy. However,, .. M ay authorities insisted on~ thy~. ori.in .l p.ans f or several : eagons $,which

102 were recognized finally by Navy authorities. It was necessary to coordina.te the entire Ay a'nd Navy sthbti in the ar a because

6peratiLonr s th'Cenitxra. Pacific area wee the most important.

'he Nyavy -Air ,"korc~e which as being,deploy d: was to be main defensive for~ce in thaefoperat'ion. .h airn rvoul$ hF v to J~l a fields which the Navy Air' 5orce would. uso And, most'iiiportant, fro . past expez'iences="of cooperative :operationi nAttu, i IS'ka and Guadalc anal, it was considered essential that t he 3=y and 'Tavy operate under a unfied''~omnmand, 'It was considered very difficult for the xi~ units on each of 'the islands to carry out. their rissions without dcrinat'e hel.p'from the ra v in regard to transporttaion, scrt, supply, inteligerce a nd. cc'mmuication. These were the supporting m~asons for select ion of' thy. Navyr to handle the unifLied command.

peaonal onuct for No rth"of -AustaliaArea

The Army General Staff decided to increase the troop strength

.n the North-of Australia area and establish a functional comDmand to corplete operational preparations in the area, At the End of October, the 2d4 xea .arxmy headquarters and t~he 2d army (both . n

Manchuria) r'eceived an order' to move to the North-of- ustraia area. The, 24 Area a;rmy was zmade up of miscellaneous logistical units;

2d Area rz~ headquarters; 2d Army, (mainly the 36th lDivision); and, the 19th Arnm (the 5th, 46th and 48th Division~s)., Mission given the.: d Ixr6a Ary commandr.bar the U'rmy General

Staff was, to repe. en~emy counterattacks i~n the T4ot1 o -" ustra1ia area .and hold the. strategic areas. In coopotration, with the' Navy, preparations were to be, rushed for our count z'acti~on,.to hold 'thy Nort -of -4ustralia area,

Operational, boundary line,. betweei, the. 8th Brea. army and the 2d Area erry was to'be longitude l0° a~t. Between thze 2d. as

A ,y and the. Southern .}rn y it 'qas to beathe line. which connected N4aassar Strait with Lomnbok Strait. Between the 2d At~rea Army and

103 the 14th.Army it was to be latitude 50 north.

The front lines which had to be held were strategic areas of

Western New Guinea and Aroe,, Tanimbar, Timor and the Lesser Sunda

Islands.

The 2d A ea Army headquarters moved to the operational area

in mid-November and assumed command on 1 December. The headquarters

was in Davao, but later it was moved to Nenado.

Prior to this movement, the 36th Division had been transferred

from China to the North-of-Autralia area in mid-October ard placed,

temporarily, under te 19th Army comander. The 46th Division was

transferred from -the Homeland to Soemba island and placed, terapora-

rile, under the 16th Army commander. The 19th Army (5th, 46th and

48th) and tle 2d Army (mainly the 36th Division) were p'laced in the

new Order of Battle for the.2d. Area Army eff'ec tive 30 October.

Also, the 7th Air 'Division, in the operational area, was placed

under the 2d Area Army operational co -,Aiand.

On 10 February, the lith1 Division, w icc sd ben in lanchuria,

was placed in the Order of Battle f or the 2d Army oon a shipping

schedule dispatchiiig it to the \rthof--Australia area. The dee-

tination of the Division was c-anp'ed to Pal3.a after transport tion was begun because of urgent. necessity to strengthen the defense of

the Palau area,

Efforts to Streingthen Shipping and Transport ation

Since the r1t'reak of war, the' number, of transorts' sunk by

'the enemy had increasd sharply and. it seemed to b e devclonin' more

seriously.

the Armyr General Staff had, in-December 19L2, first presented

a recommendation that it be allow ed to requisition 300,000 tons more

of available civilian shipping facilities. Normally, the-War idis-

t.er had supported all requests off the rmy General Staff in his position as member of the Cabinet-. In this case, for the first time,

zoo. he flatly refused because of his viecws regarding the over-all total economic picture and its supporting requirements in meting the needs for war pr'oduction. The Ar y General Staff had supported its request by stressing its belief that shipping requJroments for

imediate operations should be given priority.9 Thereafter, each time the Array )enral Staff submitted C. request for :rore ships to ca.rry out its opertions, a heated discussion occurrx.d. Contiguous

efforts wer made but only small gains in allowed ships were rce liz_- ed. Imperial Getnrnl 4 K qdcuartars plat ned to greatly increase ship, ping units and strengthen defensive _ne ^s?;ros tQ protect shipping.

The s Da escort (avy rcsponsibilityr) and t..ie ark:a .round ports

(Army responsibility) were to be bolstered by increasing fire power and adding necessary air force units for the job, especially in the area in which the enemy had air superiori..ty.

During the lat ter pert of Sept tuber 10431 t he- army General Staff carried out a reorg;anization and strengthening plan for its shipping units. The reorganiized units rero stationed =it Tjin%, Shanghai,

Singapore, Rabaul) haljaaherea and tru. In part, the added strength was gained through cons olidation of units from other areas plus special attention to the development and addition of small craft ,such !s landing craft and small fishing boats) as a means of trans-. porting supplies in the local areas, In t e latter part of December, further reinforcements were accomplished.

S teps Taken to Combat Submarines Our losses to submarines on the main rout :s between Japan and the Southern area l(Japan to Formosa and the Philip. ines g and the

Philippines to French Indo-China aynd alay)j were quite heavy

Losses suffered in the Central Pacific area were secondary. Also, it seemed that the losses suffered from enemy air actions were increas4in gradually. As a result., the Ar4'nr and Navy made a joint

l05 study and: decided, to "cooperate in, protecting shipping'.

' o accomaplis ,this- purpose, ''n.x .'ovenber' 1243 the China Exyedi- tion3.ry -Army commander and th1- lhth~ Army commander were ordered to

.shave their air. units cooperate: with the NT!avy I.i ahti-submarine

opertion.'; In,mid-Febrguary 194,9the air unit of 'ethnorthern

Army1(1ft-Air .Div:iion) were deployed 'in the Kushir6, Y;euro. and

Yuroran 'a±eas and to the 'Tsugarui and Soya Straits E lemients of the

1st Air Arai were located. in Southern'Yrs'ashu, the'Southwestern Islands and Formosa. The Commander of :oxeland Denses received an order to reinforce protection of' sea transportation in the vicinity of th~e Korean Strait. He was to use air units from the

Western District Army~ and the Korea Army.

- Strengthening of Sea 3asvs

Shipping in the Solomons and 'dew Guinea -areas' where the enemy had air superiority was :very diffici~lt. Our ldsses from enemy air and sea attacks increased sharply and the area undefr enemy control became larger. On' 19 February' l94i4.5'th~ Army Genei'al staff directed the Southern Army 'commander, the 2d Area Army commander; and the

Nortbhern Ax'~ commander to take -special pr ecautions to protect the sea bases in Bengal Bay; the North-of-Australia area and the-Kurile Islands. Objective of this directive was to make sea movements and counter~operations 'easier 'in the zone of enemy superiority and to retain the supply linies for the strategic points in our peni- meter. This was a recognition of the vital necessity for fortify" i 1g harbors and bases against' air and sea attacks.

The items with which the bases had to' be equipped 'were shelter- ing installations for small boats; small boat maintenance units; communication installations; base units (anti-aircraft units, if possible); navigation markers; necessary line of communication installations; 'and stockpiles of munitions and fuel. The sea. bases would be classified as sea combat bases and sea line of communication

l06 bases. They were; to be used- bye bDrpedo boats 'and -fpree which were to take part ton short ran~ge e a at..Also; they ;were to be used as stanidby and. ass embly points fs r amphibious: groups.

Enemy attacks on shipping-.had .arceed us to rely on. railway transportati i The : i roads -of Korea, Manchux'iaf.China, French

Indo-China, :Siam, Malay and Burma had to, be imp twit n 0 February, tshe .Army 'xencerel staff decided and initiated a reor-~anization plan for rein1'orcv.ment 'of -railway u~nits to, strengthen. railway transportation,

Aprv1o mhlop t~n ""cpration) The Burma area wa~s bf strategic value because of the Burma Road. If we cut it off, it would be advantageous both politically arnd strategically. It had also a. great 'value as the northern wing of' the Southern area. There fore, we estimated thy: British and Chinese Armies would use 'their main .fort:es in ,.this area... In. anticipation, the Army General Staff and the Southern Army,._.ttached .importance to this area, and planned to reinforce its strength~. ,Bar the beginning

Qf 1914, the Burma Area Arm, commander had, under, his. command- the

15th Army (15th, 18th, 31st,. 33d and 56 th iviaims).; the 28th Army

(2d, 54th and Sth ,Divisions);s. and., the .24th Independent .,ixed Bri- gade. In November 194.3, the 53d Division (in. Japan) was. ordered to leave for' the._ Burma area to, be under the Southern Army .commander. These forces proved. to, be insufficient, to take command of such a wide area. Due to the concentration of the lristish army (approin' ately 3 divisions), and their op:erational preparations in the state of Assam, the intense, air transportation between India and China, the situation of a newly organized 1st Chungking Armay (2 or 3 divisions) in -the. Bukawng River Valley area, and the strength of the. Chinese Army in the Yunnan area (approximately 10 divisions),

it became .necessary -to keep a close watch on Northern .Burma Opera- tions.,

107 At the end of Dec e:mber l943, the. Southern Army~ conmarider secnt his Assistant Ch of of Staffto T1kTo to .make a recommendation to the Army eneral Staff concerning 'a- contemp1ated offensive op ration

(1u1 1ph1Oertin7i Ever since the completi on of the 1st stage of tvhe Southern Operations., repeuted studios hatd been madec by the Southern .Army commander, and rmy eneral Staff regarding such an operation. The opera tiona ,..plan prese-nted by the Southern Army commander called for latmnchipg attacks from the east and soyuth during the spring of 1944 using the 15th Army, composed of tbree" divisions.

The objective was to annihilate the mhenrr in the Imph .l Basin, The Army General Staff brought up several questions regarding the proposed operation. There was a high possibility the enemy would attempt a landing on the coast of Southern Burma from Bengal.Bay,

If the '{UUr Operation were carried out, would we be able to carry out countermeasures, patisf actorily.? After capture, the Imphal area would require a large force to hold it. Would this weaken the defense of the entire Burma area? Could ground operations be carried out successfully even thou.gh our air strength was inferior?

Would we be able to maintain our supply lines? Lastly, was the "UL"Oeration sound?

The Southern Army c ommander f elt it was unnecessary to worry.

He insisted that capture of the Imphal area would niake the general def ens e of Iurma easier. It was his belief that the terrain fea- tures of the area would allow us to defend Western Burma with a smaller force than was being used currently. The Army Gen era?. Staff rcognized the necessity of a strong defense .for Burma. The t"U"

Operation was approved. On 7 January, directives were issued,

The Southern Army commander was authorized (as an operational method in the def ense of Burma) to launch: an o±f nive operation against the import~ant area 'of Northeastern India centering on Imphal.

After crushing the enemy, the area was to be secured.

108 The "e Opration was begun on 8 !&-,rch,

Xnst uctins fl~cr f' "Phi wGott '(Human.i wn i)O;p ration

:3e inning in thQ. autumn' of .1943, the Army General Staff made studies regarding future operations to .oapture key points along the

Hiunan-'wangsi anid Canton- iazWlu railways. Ao ir uldd wosthe sout':i,rn part of' the Peiping-.Hankou railway. This operation was to be called the . tJchiCoUr Operation.. There were four objectives stu~died for the proposed operation.

1. We were to seize -potential .Ameisin 1B-29 bases at

Kweilin and Liuchow. This would help in the def ens e ot'our iHomeland. 2. By consolidating forces in the Kweilin r:zd. Liuchow

areas,, we would engage the e emy moving into the Soutth China area via India,, Burma and Yunnan,. 3. Because sea transportation was deteriorating, the

railroad running north and south via French Indo- China would be r~pai red to establish a reliable land

transportation system for the Southern Axmy, L.. We wr, ld plan to weakeni the Chungking Gove~.rnment by crushing the Nationalist army.

After several investigations,, item. 1 was the only one a~cepted.

The ,decision to " arryr this plan out was made in January' 19141. On 214 January, the Commandr, in Chiefs of the China ExpeditionarRJ Asrmy and the Southt;rn Arty were issued orders which stated;, plans had been made. to destroy important c icmy air bases in Southwest ,

.Qhina, the China. Lxpeditionary Army co iander would mako attacks.

.94a the WHunan'-Kwangsi aned Canton.-Hankou railroad; the Southern Ary was to cooperate.

Outline of the Peiping-Hankou Operation provided three items~.

1, In, April 19141.,., the North China Area Army would begin~ the operation -from ?North China. It would. crush the

109 enonry arid seizethe. sodthern portion of the Peiping-

Hiankou&railroad south: of tixe Yellow' fiveor. these

Operations were epected to. take about' a month and a half.

2. Strength to be. employed was establi~s hod as the 12th Army (composed of four divisions) of '-the Morth China

area Army ' nd a' part of the 5th Air' i rrr .

3. After termination of the operation necessary units

from, the above--mentions d forces would be used in the Hunan--wangsi Operation.

Outline of the Hunan-Kwangsi Operation included six points.

1. In June lily.. the 11th fry would begin operations from the Wuchang -Hanktu area. In July and august,

the 23d army would begin operations from the Canton area. These two Armies were to rout the enemy and occupy the vicinities of ;<.weilin an~d Liuchc: . e mnants of the enemy along the iunan-Kwan_si and, Canton--Hankou railr.>ads were to be mopped up. The

openatL:_ns were expected to take apprximately five months.

2. According to the situation,. an operation to destroy enemy airfields in the Suichuan and Nanhsiung areas

would be carri.ed out as so:on as possible after the above operations.

3. If the situation permitted, the 23d Army would make

another attack against Yungning during January and

February 1l/1t and clear the road, betw :en Kwlin and Langs on,

L.. rioz' to the launching of the 11th Armys operation,, the 5th Air Army would carry out 'operations to destroy the American.-Chinese Air Force,. thus

gaining air suprio rity. VJfile suppressing the

110 rise..,in .;knervy ,air Apo r, the. 5th .AixrArmy would support ground forges drectJy.y zt critic..~ times with the necessary forces. 5. Strength to be used for the .,peration was to include:

11th army (from sevemto eig ht diis ins )

23d 1 MY (two divisions),,

forces directly under the xpeditionary Army (from 0on6torz two divisions) 5th Air Army u The South ern

help the China Expo ditioonary rm T in its campaign.

During the early and middle part of' February, the strength was

increased. The 3d ' Air Division under the China Expeditionary Army

commander was reorganized into the 5th Air Army. It had approxim- atelyy 250 planes. The 27th Division in M~anchuria, the 116th Divi~- sion and miscllaneous axits from the 13th Army were placed in the Order of Battle for the 11th iyx'iy. The 22d Division and mfiscel-

1Mosunits from the 13th Army were' placed under command of the

23d' Army. This operation was to be conduct .d under difficulties such as

the lack of gasoline 'and. ships and was. to cover' an area of 1,00

kilometers, It was to be carried out with 400b,0a00 men, 70,000

'horses arid 12,000 vehicles. The way in which the )line .4' communi~- cation operated wou]ld have a great influence on the outcome. The importance cX3 transportation brought about the following special pe nts' of op v tiorls as directed by the Army Genera. Staff; 'For the preparation and start of the vpration, use of large type

ships would be kept to a minimum. Water' routes were to be used to thoir utmost advantage. Railroads would be repaired as soon as

'Possible to economrize n fuel. H'ospitals ini China and Souther'n

,-nchu*ri&Would be enlarged and ineasures to prevent malaria and

x.11 combat pests would be carried out. .The s otor Transportation units which were transf erred from Manchuria would be re'grouped. as soon as rough completion of the operation was assured. to prepare f ,-r futuore operations. The Peiping-H-anikou and Canton--1ankou Operations were started on

1=3 April and 27 Nays, respectively.

Intructions for Various Areas

When Italy surrendeered on 8 September, the Army General Staff ordered the Comanders of the China Expeditionary Army, the. Southern

Army, the 14th Armyr,, and the Governor, Genera. of. I-onkong.to hal~t

Italian activities in their operatio.nal areas and to, isarn Italian

Forces.* These included some Italian Naval Landing Units stationed

at Shanghai and Tientsin; the consulates in China, Lail anc, and

French bIdo-China (the latter two are not confirmed for Thzis action); and a small number of merchant ships and Italian nationals in China,

the S uthern Area and the Philippines. All Italian citizens were

placed under close, ilita ry Administration surveillance. To strengthen forces, in the Southwest, thejth Oi.v.sion (in

Japan) was placed in the Order of Battle for the 25th A:rmy. in late

September 1943. On 10 December, thy: Indo-China Garrison J:xmy was organized (21st Division, 34jth Independent ixed Brigade and various units under the direct control of the tray)., On the same, irate, the

Siam Garrison Armay was organized (29th Independen t Mixed,Brigade and units uder direct control of the i=army) . In maid-January 1914, the 29th Army was organized (se:ve ral inde peode nt garrison. units) . The 29th Aramy was .Jv;--.n an >nat inNoten alT

In late 1943, defense of th~e Sumatra oilfields was considered very important. To help this situation, the 9th Ar Division wa~s

activAted. The Baiigkalang-BErandon Defense Unit and Palembang De'-

fense 'Unit were incorporated into the Order of Battle of the 9th Air' Division which was placed under the 3d. Air Army.

112 In the. early part- of January 144,7 guard ?un.,sy° s guard units,'614 specie7J.guard cnmpanie ..aid )speca J.:uard 'engine or units were organized in rderc tso strengthen the gfuard 'of the Mome- land and Korea. These units were placed under appropr iat ; cyiinhanders.

The '42d Division was s flt t5 the uri.E s arce to r 'einf. rce defenses there. It was plac d" Wider the Northern Army- comnander

Additional Constructi .n and "vintenanee Plans fL.r ir Bases

Considerin , past exp sriences in azaph ibiou's def Ensive operations, the yezr~r General Staff realized that the beft, defense came from the

Air Force situiated in the networ'k of air 'bases"a loingyth~e main' line of defense. In the latter part of January 1944., orders werc'ibue d to construct and maintain air bases covering the entire defcrsive zone until the end 'of 19)44. The main purpose was to coordinate and perfect, air defense. This w Ls done yr grouping "several airfields into a system 'd c6entrap y organized air base areas. * .r6 a. resut, a concentratd air force could be Thaount ed more qick .y ' nd "off ct- ively. For proper functioning of, the system, an effective c m-n nrnication, repair and supply s b m ha d t be proided. The large air base areas would be 'used by one air divisibta. The "ordihazr air base areas were to be fortified. Locations were to' be fixed in depth, as much as possible, iii accordance wth the ground force oper-.tional area policy~ ls o, ' to be taken iiit '' consideration on locations wits the r elationship with the air' base are.as i n the 'front lines ; f our cuter defensive soh ro. In additioni to this-system oAir base areas, emergency fields to. support the military air routes and' air strips were to, be constructed. speedily.

113 PART II Second Stage (March June 194h)

Situation review an~d Estimated Enemy Plans

Because of the penetration of Vitiaz Strait by- enemy- forces,

the 8th Area Army at Rabaul was -isolated comgpletely. Sea transportation to the 16th Army in eastern New Guinea was endangered seriously.

This became more critical in late April when the Enemy landed in

Hollandia and Aitape. The enemy landed on Sarumi and Biak Islands

in the middle and latter part of May. Eastern New Guinea was cut off from the North--of--Austraia area. It seemed the Southern area

defensive sphere was beginoning- to collapse in this corner.

On 8 March, the Burmia Ar ea 1,r r had started the "V" Operation according to the plan. In its first phase, it progressed smoothly.

M'unipur was invaded in the, latter' aprt of "larch. Kohima was captured on 6 April and the attack. against Iraphal was commenced,

Before Imphal was captured., eney planes cut off our rear and

severed our supply- line:. The enemy was able to support its units

through air transportation ai.d our operation was checked.

In the Hukawng River Valley- area, our 18th Division encountered enemy coutterattacks and was forced to, retreat,: Due to the i.nva-

sion of Northern Burma by- enemy airbor'ne troops anid the failure of

the fUJtt Operation., the situation in the Thuria area was at a stand- still.

The enen r attacked iPalau in the Pacific area in the latter part of ''arch and inflicted he avy damages on our ships. Powerful enemy land, sea and air forces began an offensive operation against Saipan on 15 June-. The 1st ' obile Fleet took part in the naval battle off the I'arianas en 19 June. Our Air Force suffered heavy damages. In early July, the main force of the uni~t of S ai , an was annihilated and the island fell into the enemy's possession.

Our forces in the China area began the 1st Phase of the "Ihi-Got" Operation in mid-April according to the prearranged plan. The 12th Army in North China executed the Pc.Iping--?ankou Rail-wmay

Operation and successfully completed it on 9 7May. The first phase was completed and the Hunans'Kwangai, Operation was begun the carly part of May as thy: second phase.

The United States Air Force based in Chita made its initial air raid against Nlorthern. Kyushu in midtJune. The enemy commenced landing opera tions in IEurope to open the 2d Fr6ht in the early part of June, After conclusion of the first stage -of the first phase (the Southern Operation), our Armay had made preparations for defensive warfare, ex~pecting e-nemyr attacks from five dire ctions: 1.Fromn the leuatians aainst" the Kurxile Islands

* 2. From the Centr:al Pacific against the l om land or Formosa and the Philippines 3.. From New Guinea against the Philippines via the Northr-of -Australia area

L From the Indian Ocean. toward Java and Sumatra

50 From Burma toward M~alay and Sieii Reviewing_ the situation following 'thempadle of 1.9h3, it had been assumed that an American attack from the Pacific area and a

combined Amorican.-Britishm.Chinese att ck. from the Surma area would be the mnost probai e.

~romF -. xtumn of 1~942, enemyr attacks. in' the Southeastern area being directed from the Pacific .area were -.s ucc ssfual because they were c insistent. The enemy tactics had. been to' adVince against the

*Gilbert Islands during autumn of 19143 and the - attackcs against the

M~'arshall and Truik areas in February .91a , they changced their tactics to leapfrog perations t sing the stren ti of their fleet,

The enemy' s strength reflected, their jntrie l powe~r and could not be ignored.

1.5. We were. unable to Judge, definitely, whether the enemyj would attack Japan directly, or wait until after invading the Philippines arnd Formosa. Considering the .strategical valuie of the Philippines and the difficulties involved *iri-making a direct. attack ag7ainst Japan, it was more tharn probable the enemyr would atta.ck the Philip- pines. first. Ifl this woo-~ the Southern area would be. cut off from the rest. of, the Empire. In such case,. the enemgy probably would. conduct a diversionary operation in the Kurile area. It was un-. predictable whether the enemy wouj..d attack the Philippines and Formosa from the direction of the Mj~arianas, or the Southern i1hil ippines from the direction of New Guinea and. the North-of -Australia area. According to logical anialysis, however,, the .enmy probably would 'carry out the latter operation.

Contributing to our problems in the Burma-Thailand-~French

Indo'China area was the weak sit uation which c onfronted us in Thailand and French Indo-China. In each of these. counrtries,We were operating by mutual agrexient with the gover ents concerned.

In neither of the countri .s did we have a military administration. Our presence w4as based on diplomatic agreement. With the trend of the war- beec mnng unfavorable for >Japan, there was sorte evident dissatiffaction on the part of the people. This unstable political. situation was a. complication to be considered in future operations anpd could' be disadvanitageous to us in case of an enemy counterattack htoughi Burma. If such' an enemy attack were successful, it was anticipated' that it would encourage the Chinese to now efforts against our forces in China proper,

Disregar-ding the 'battle situation in Europe, the United States

AM was eTected to concentrate its main force in the Far East area.

.The- decisive campaign was considered close at hand.

Even under these circmnstances,' it was unnepessary for our Army to alter the operational plan established in September 19L 3. Hlo-

116 ever, preparations for thy: decisiv~e battle had tci'bepursued dill- gently including such things as reiniforcing defensive positions in the Central Pacific area; establishing' defensive positions on Formosa., the N ansel 3Islands and the Philippines; strengthening the defense of the Hfomeland; bolstering t ho protection of' our shipping,; increas-

ing thy: production of airplanes; and, making research on and pro- cueing radar equipment.

North-of-l-ustralia Area Inst2xutio's. Communication between Riabaul and New Guinea had become difficult

due to the' eneirr's penetration of Vitiaz Strait~~ The Army General.

Staff -realized it would be difficult for the 8th. Area .Army co nxandr,

under such circumnstances, to command the 18th Army. A ter studying

the systemn of' command in this are~a, the Army Gneral Staff issued.

an order u'-n 1 arch 1914. for the 18th Army and the; hth'Air Army to be transferred frbxn the '8th Area 1=rhiy to the 2d Area Army.

Duties of the 2d' and 8th hrea Armies were revised-

1. The. Armyr General Staff planned to hold the 'Rabaul and Marsh .l. areas as long as possible, while establishing

f'ortified positions in the area extending from the North-

of-Australia area to the Central 'c area in order to repulse enemy counterattacks. It was ,planned to

take thr; offensive. when an~d if the situation permitted

'and to disr'up the enemy' s war *plan,.,.

2. The, rth Area 'rm commnder would coopQ~ra~te with the lAavy and heild the Important RPi al . ar as long as possible to =rmek6~'oeations easier in th area ext~end

ing from the North-of-Australia area to the Central Pacific area,

3. The 2d Area Armay commander would carry out his original

duties.. With newly assigned units in eastern New Guinea, he would also plan t ohold the area west of aWewak end

would make an effort :to check any enemy. advances tow rd

the western Nlew Guinea and western Caroline area,

i40 'The' opaeratinal boundary between the 8th Area Ajrmy and

the 2d area Army was to be lonritude 1h7 ' east passing

through thc eew Guinea and Bismarck Archipela>oarea.

The Admiralty Islands were to be included in the opera-

tional zone of the 8th Area Army.

In connection with these or'lers, the Army General Staff issued a three point directive to the 2d Area Army commander.

1. The 2d Area Army commander would withdraw the main force

of the 18th army to the area West Qf Wewak to strengthen

defense of the air bases at Hollandia, :itape and Wewak.

The 18th Army, also, was to check the enemy advancing

against western New Guinea and the western C rolines,

If Enemy landings were made dring' the abovementi ned

redeployment of the 18th rmy, an effort would be made

to annihilate them.

2. The 2d Area -armycommander w uld accunmulate the maximum

amount of munitions in the hollanclia, A itape and "e, ak

areas,

3. The 18th Army1 s operation was n ot to be allowed to

interfere with copletion of the 2d Area Army's opera-

tional preparations

In accorciance w ith previous instructions, the 2d Area Arry had already decided to held the, line extending from Tanimbar through roe to Serumi in Western New Guinea, with the area surrounding the Geelv- ing Bay as its center. It was planned to establish the region around the Gulf of Geelving as an air base and the 2d Area Army was endeavoring to complete operational preparations. The i'my General

Staff had no intention, at tois time, of altering the front line although the 18th zm'ywas attacohed.. to the, 2d '=rea rmy. Its mi.ssion

WaS to hold the area outside the 2d area 'rm ys front l ines.

First and Second MJdificatio' ns _f 2d Area Army Front Line

On 15 April 19W44, the 2d area army (on ,rder from the Army Gener M

Staff) was placed under command of the Southern Army. In the latter part of April, enemy forces landed unexpectedly in the vicinity of

U~ollandia. As soon as our 6th Air Division in this section lost its fighting ability, the area of enemy air superiority, again, increased.

Regardless of this fact, the 2d Area Army desired to attack -the enemy beyond our front line with its ground forces. Howuever, the

Army General Staff could not send any additional air and ground forces into the area. The operation in this area assumed the position of a delaying action to be carried out by existing forces. It seemed impractical to employ the troops and materiel being transported to this area for an offensive operation in the forward area. In order to accomplish the Army General Staff plan, establishment of a new defense line in the rear had to be set after considering the total area covered by enemy air superiority. It was the responsibility of the Army General Staff to advise the front line troops regarding this rear line.

On 2 May, orders issued to the Southern Arnmy commander relieved him of his responsibilities in the eastern New Guinea area., The 18th

Army and other units in eastern New Guinea were to be transferred to western New Guinea.

Instructions for the Southern Amy commander included three points;

19 The front line to be hld in the western New Guinea

area would be the line linking the innermost sector

of Geelving Bay with Manokwari, Sorong and Halmahera,

Important positions in the vicinity of Biak Island

were to be held as long as possible. Necessary troops

would be sent to the island from units in the Sarmi area.

119 2. A part of advanced units of tht 35th Division which were

transferred from China in early April and were to be

located on the St Andrew Islands could still be sent

to such places as the Mapia islands.

3. The 18th Army and other units in eastern ijew Guinea

were to be transferred, inmediately, to western N w

Guinea. .Any enemr landings in the area would be

checked to make all operations easier.

The enemy air force having extended its operational area to the west had caused shipping transportation to the ?Ianokwari area to

beomne more difficult. The 2d Area Army commander had been plan-

ning to send the main elements of the 35th Division (stationed in

Sororig at this time) to Manokwari. The Army General Staff decided.

it would be better to leave the division in Sorong for its defense.

Stopping the movement of t he 35th Division brought about the second

change. Instructions issued on 9 May stated that the front line

to be held in the key sectors of the western New Guinea area was to

be the line in the vicinity of Sorong and. Hmaaera The important

positions of Biak, Manok ari and near Geelving Bay were to be held

as long as possible,

After the enemy landed on iak Island during the latter part

of May, communication between the 2d Area Army and the l8th Arrayby

either land, sea or air became impossible. It was then impossible

for the 2d Area rayr commander to command, effectively, the 18th

Army. Also, the withdrawal of the 18th Arm r to the WIestern New

Guinea area (ordered by the Army General Staff), b:cane impossible.

As a result, the 15th iirmy was detached from the 2d Area Army and

placed under the direct control of the Southern Army on 20 June.

The Army General Staff had the Southern army commander order the

18th Army and units in the eastern New Guinea area to "hold to the

end" the important regions in this area. This was directed to make

120 over-all.-operations...easier.

Northeast~ri Aea Instructions Considering possible enemy' attacks against Hokkaido from the Aleutian area., def ensiv&* positions' on Hokkaido and the Kariles had been reinforced. As a result of studies mad'e on the character of the Northern r ray ih spring. of 194hL, it' was deemed necessar to change it from a district armyr to a cdonplete operational army. It was designated the 5th Area A'rry arid was responsible to the Chief of Army General Staff. Operational bou~ndaryr between the Eastern District Army~ and the 5th Area Ary: wasocanged to the Tsugaru Strait.

The 27th Axry headquarters was drgani ed for def nsjive purposes in the Kur'il: area and ,lace~d under' the 5th Area Army commander along with the 1st Air Division. in mid-"iarch, Army Genral Staff issued battle orders for the 5th Area 1A:myrend the .27th rmy.

Orders for the 5th .area Army

1. Plans for the northeastern area providod for rendering

the enemyl plan of attacking the Homeland impracticable

and for prevention of a war with Russia.

2. "the 5th ..area Are~ com n. nder would cooperate with the Navy, in expediting opor.tibna17proeparations for the

purpose of interc eptirig ' ny 'enemy~ attacks against the Homnel'and in the INorthe, st ;r area. 3. Operational bounda y' butweei 'the '5th Axiea Army and the Comarander of Homeand Defense was to be 'the Tsugaru Strait. This s trait and the Tsugaru Fortres area in

Aomori PLref cture were to 'be uinder the command of thIe nth Area. Army.

1.21 Formosa and: Nansel Islands Instruc tions

Anticipating future enemy attacks from the .Marianas and Philip- pines areas and surprise attacks from other directions! the Army

General Staff realized the necessity: of speeding up prep.rations in the Formosa and Nansc4i areas. In the' latter part of March 194, the battle order for the' 32d Arm y was issued. it' .:and the Formosa

Airmy were ordered to rush operational preparations. This was called the :10th Oper o ional Preparation.

-Organization of the 32d Array

32d Ar, headqurters

Aai-Oshima Fortress Unit

Nakagusuku Bay Fortres Unit

Funafuchi Fortress Unit

Units under the direct command of the Army

Orders issued to -the Formosa army and 32d army corn naiaid rs included four points:

1. The I.rmy Genm.ral Staff planned to strengthen defense

of Southern Japan.

2. The 32d Army commander would cooper~t. with the ?,!Ivay

in expediting operational prep rations. Hdo would 'be

'responsible for defense of the Nansei Islands,

3. .The Formosa Army commander would cooprate .wit~h the

Navy in expediting operational preparations . pec would

be responsible for defense of Formosa..

4. The boundary between the defensive areas of the 32d

. rmy and the Cormander of Hlomeland Defense was to be

latitude 3 0 0101 north. The bou~ndary between the 32d:

Armwy and the Formosa Army was to' be longitu~de 1220301

east. The boundar between -the 14th army and the

*Formosa- Ai r was to b~e l.:tituide. 200101 north.

122 Objectives of the operational preparation which was to be ex-

eouted by the Formosa A°rmy and the 32d Army were to maintain defense and transportttion between Japan and the Southern area. They were to be prepared first to repel any enemy surprise attacks and then to meet orthodox eneny landings.

Air operational preparation was to have top ,priority. Othe;r

items were to be considered secondary. Countermeasures against.

unexpected attacks were to be. carried out, immediately. General

operational preparations were to be completed by about July l94h.-

In connection with air operational preparation, several air

bases were to be constructed in the area extending from the east

coast of Formosa to the Nansci Islands in order to make air opera,

t"ions easier! Enough bases were to be, developed so that approxim-

ately one air d:i.vision each could be deployed on Eastern Formosa

and the Nansci Islands, The amount of materiel to be stockpiled, before July was expected to be sufficient for two air divisions.

A1fter that, it was to be. enough to. fill the needs, of one air divi-

sion.

Ground forces were to be developed to protect air bases and main anchorage points. Part of the ,troops were to be dispatched to the Daito Island area to cooperate with the Navy in building airfields. Part of the Formosa Army ws to be sent to Batn Island for its defense.

Two Independent Mixed Brigades and the 28th- Division (from

Manchuria) being assembled in Shanghai were assigned to the'32d

Army in the early part of M~ay and in the latter. part of June, respectively, The 50th Division and newly orgaized 8th Air Division were assigned to the Formosa Army in the early part of Mtay and in the early part of June, respectively,

To consolidate supply op rations, the Army General Staff assigned and transferred from its direct command the 32d Army to the

12, Western Arry 'in the early -part of. May., This wsas, done because the

32d and Western: ArmyIs'supply situations were closely related.

Southern i rea Command System Unification

In June 1942Y the 11th Army was placed under direct control of the Army General Staff. At the beginning of 19144, it was recognized that a unified command by the Southern Army was necessary in the

Philippines and North-of-Australia areas. Steps were taken in the latter part of March. Reasons given for the unification included three points.

1. It was certain the i-=erica.n iArmy would direct attacks

against the area extending from the North-of-Australia

area to the Philippines. The most urgent counter-

measures against the enemy attacks would ,be made by our

air forces within the defensive sphere. It was neces-

sary to unify the command system to get the right

concentration of the enire air strength at the right

place and at the right momenta

2. Because shipping had to be carried out by a limited

number of ships, it was necessary to transfer interiel

within the Southern area through local transportation.

This system had not been developed .effectively due to

opposition by the chain of command,

3. In order to enable the Airmy General Staff to cofmmand

effectively the over-all operations against enemy attacks

from all directions around our defensive sphere, it was

necessary to ?reduce the number of area army conm and

organizations.

124 Change, of Miss,' n and Instrutiot fob Suthern Army

The Army General Staff plan was 'to hold the strategic regions

of the Southern area and the Northern and Central Pacific areas, to

destrdy'the aenmy t s. 'ighfingt power 'and to render the enemy's ten-

tions impractical. The plan also required every possible effort

to destroy the Chungking Government.

The Southern Army commander was to cooperate with the Navyr in

hastening operational preparation and maintaining security of

strategic areas in the south. The advancing enemy was, to be annihi-

lated. Defense was to be enforced in the Andaman and icobar Islands,

Malay, Sumatra, Java, and the Dutch East Indies areas. Burma, Thai-

land, French Indo-China and the iPhilippines were to be secured in

cooperation with their governments. An air -ffersive against the

India, China, Australia and New Guinea areas was to be carried out

at an appropriate time.

The program of self-subsistence in the various areas would be

strengthened to cope with the development of the war situation,

Defense of the regions having an abundance of natural resources would be reinforced. Completion of military administration would be rushed. Also, the Southern Army would cooperate with the Navy as much as possible in protecting sea transportation.

The operational boundary between the Southern Army and the 8th

Area Army was to be longitude 1470 east passing through New Guinea and the Bismarck Archipelago (the Admiralty Islands were to be under the 8th Area Army). The operational boundary between the Southern

Armyr and the Formosa Army was to be latitude 200 north.

?alau Island was to be in the operational zone of the 31st Army.

The St Andrews Islands were to be in the operational zone of the Southern Army.

In connection with the line of communication, the Southern Army commander was to concentrate on the adjustment of the relation he- tween. air and ground supply routes so emphasis could be placed on meeting needs of the Air Force. These were expected to increase sharply. in addition, .steps were to bhe-taken to -assure unrestricted

exchange of materiel in the -entire 'southern area,, Local self-

subsistence was to be applied more ,completely. The Philippines were to' be established as the supply base for the Southerni area, especial-

ly the North-of-?Austtalia area,

Terminal 'supply points of the Army General Staff t

TERMLINAL POTINT AREAS -SERVED. Manila Philipoines'

Saigon (this.' point.' to. be trans-- ISurma, 'Thailand and' French ferred to Singapore if Indo-China necessary for Burma area) 'Singapore' Malay, Sumatra, Java;' and Borneo

Halmahera and'.Palau : ' North-of-Australia...: If circumstances. perm itt ed, supplies for the N'orth-of -Australia area, were to-b,6 sent directly to IMano1wari, Sorong and Anmboina,

Materiel hitherto under direct control of the' Arc-r General .St~ff in 'the Philippines° was to be transferred to the Southern Army.' 'In

general,.. the 'Army General Staff would not deliver war supplies

directly to subordinate units of the Southern Army, .but-- ,ould deliver exclusively to the Southern Army.

Headquarters for, the Southern Army was moved, to :Manila, from

.Singapore,' and the, command system became completely unified.

As. part of the reorganization. of the command system in the Southern area, the 7th Area Army headquarters was newly organised in. Singapore to assurne command of the 16th, 25th and 29th Armies,

The. 24 and. 7th~Area, Armies, the lath Army and' the 4lth Air' Army were *assigned. to the .Southern Army,..

To. conduct - ir, operations within our,,defensive sphere, it was necessary to organize 'aunified Ai:r ~,Force headquarters. However, this was estimated ass being a .co picat5n in the command system.

Thus, Southern Army headquarters assumied commnand of ta~e ai:force,:

The 3d1 Air' Army (5th and '9th Air Divisions) was stationed.. in the Singapore area on. the Western Front., The .4th Air Alrmyr< (7th ir.. Division) was stationed in' the Philippines area on the Eastern

Front,.TExpcting the decisive campaign to take place in. the Phil.ippines, it was planned to increase air strength. The. 2d and 4th Air Divisions were transferred to the Philippines from Manchuria in mid-May.

At this time, an unusual, split in the organizational structure.

and responsibilities of' the 2d and 4ith Air Divisions: was. ordered.,

All flying units of' the two divisions were placed. under the command

of the 2d Air Division commnander. All service units of both ivi~ sions were placed under the 4th Air Division commander. Thus,: the

2d6.Air Division: became a flying division', exclusively, ". nd, the 4th Ar Divisioni became an. air service unit,, solely Purpose of .. such:.reorgah izatioz has -been expressed as a. solution to the c.onro .. , and concentration of air attacks -and. to enpediting " air base: con,- struction ii specific operations.. The 2d. Air .Division. (flying units) was assigned directly to the. Southern Army while the' .4th Air .Div.-. sion (service units) was placed under the 4th Air Army. The rmission~

assigned the 4ith lAir Divisi=n was .the construction of' air~ba s .in

the Philippines." On; its arrival in the Philippines (late.May)) the

ed Air Di vi ijn wn s laced .under the .4th Ai Army" by. the. Southern,

Army comnnander,

To strengthen the defenseoapacity in. the Southern area)y the 32d Division, (from 12th army in North:>Ohina). was iplaced. under the 14th Army command.er. The 35th Division which had been tra~nsferred from.China anid placed. under t he .3lst ,Annry -eominrder was .reas'igned to the 2d. Army in the early part. of "April.

127 The 33d Army (18th and 56th Divisions) was newly organized under the Burma Area ^frmy commander on 11 April. It. was- activated for the

purpose of establishing a strong command structure in the important

Hukawng River Valley and Yunnan areas. By this move, it was plan-

ned that the 15th Army could be relieved of some of its responsibili-

ties in those areas. In this way, the northern flank would be made

secure and the l5th Army and the Burma Area Army could concentrate

on the projected "U1 Operations.

The 32d Division, recently assigned to the lhthiArmy, was re-

assigned to the 2d Area Army in the latter part of April and sent

to the Hialmahera area. The 30th Division (from Korea) was assigned

to the 1l4th Army and sent to the Mindanao area.

Due to the battle requirements in the Burma area, it became

necessary to reinforce troops in the Southwestern area. The i9th

Division (in Japan) was assigned to the Southern Ariry in the latter

part of Maay.

As an aid in future operational preparations and to ease the

burden of responsibilities for the line of communication in the

Burma area, the Army General Staff organized the following units

in the early part of June:

Southern Army Line of Communication Inspectorate Section

Burma Area a:rmy Line of Communication Inspectorate Section

2d Area .I.rmy Line of Communication Inspectorate Section

These sections were assigned to their indicated respective Armies,

In order to reinforce the defense forces in the Philippines,

independent mixed brigades and other units which had been sent to

the area were reorganized, The 100th, 102d, and 103d and 105th Divi-

sions and two independent mixed brigades were organized and assigned

to the lhth Army in mid-June.

Over-all preparations (No 11 Operational Preparation) for the

possible decisive battle in the Philippines had been put in motion

128 by an rny General Staff Directive in May 19414. Preparations were to be. roughly completed by the end 'of'summer:

Central Pacific Area Instructions

The 114th ,Division (from Manchuria) had been ordexbcd ."o move into the North-of-Australia area to come under the command" bf t he 2d L.rmy.

Because of enemy. operations in midi-March, it was necessary" to rush the defense of Palau, As a result, the destination "o± the :11th Divi#- sion,, already en route, was changed to Palau on 20 March -and it was placed under the 31st jArmy.

Using practically all. available shipping,, the arrmr and iavy conducted. a, prompt and effective deployement of strength in the

Pacific area during the spring of 19144$ In spite '©f-heave damages resulting from enemy submarine attacks, our defensive positions gradually were improved. The Mariana Islands and the Ogasawara Island areas were of vital strategic value and it'was considered essential to further strengthen them. The 29thVh.visiOn' was trans-

(erred from Saipan to Guam in the early part of 1 pril. The 13d.

.Division was .shipped to Saipan from Japan. The 109th Division was organized from troops on Ogasawara Island. Outline of the 31st Army's order of battle in the latter' part of May: 31st Army headquarters

Group in" the Truk area: Gp Cmdr S2d Div Cmdr

52d Division

.,lst. Independent Mixed Brigade 52d Independent Mixed 3rigade

11th.. Independent .Mixed Regiment

14th South .Sea Detacheit

Miscellaneous units under the direct command of the Group Commander

Group in the Northefrn Maiana. area: Gp Cmdr h3d Div Cmdr

43d Divis ion

129 47th Independent 'Mixed -Brigade

9th Independent fixed ,Regiment

Miscellaneous Units under the:direct command of the Group Commander

Group in the Southern Marianaa area: Gp Cmdr -- 29th Div Cmdr

29th Division

h8th Independent Milxed Brigade

10th Independent Mixed Regiment

Miscellaneous units under the direct command of the Group Commander

Group in the Ogasawara area. Op Cmdr -- 109th Div Cnidr

109th Division

.12th Independent Mixed Brigade

Miscellaneous units unde r the direct command of the Group Commander

Group in the Palau area: Gp Cmdr - -L4th Div Cndr

lhth Division

19th Independent Mixed Brigade

53d Independent Mixed Brigade

Miscellaneous units under the direct"command of the Group Commander

Miscellaneous Groupss for.other areas: Command - 31st army Gdr

~0th Independent Mixed Brigade for Yap

1st ,mphibiius: .Brigade for Marshall and Eniwetok-:

..- st South Sea Detachment .for .Marshall

:2d South Sea Detachme~t. for Ponape and .IKwsaie

13th Independent Mixed Regiment :.for Wake

Miscellaneous units under the direct command :of-the.31st I3rmy

1'AGQ' Operations in Mariana AUrea

During March and April 1944, Imperial General Headquarters planned to fight a decisive battle with the enemy advancing from the

Pacific area and conducted surveys which were called the "'L-Go 1 Opera-

tion. This was known as the naval battle off the Marianas (Philip-

130 pines Sea Battle)-. *Theenemy situation as estimated by Imperial General headquarters ,in the early part of May indicated the enemy's operational preparations in the Central Paciic and Southeastern areas were being carried out steadily. A direct attack against

Japan wa$ not expected until after the capture of powerful offensive bases in the Philippines.

We could not determine whether the enemy was planning to advance in the Central Pacific area ater extending General MacArthur Is offensive line to the North-ofNsAu.stralia area, or begin the Marianas and Caoline Qperations at, the earliest possible' chance regardless of the progress of Macrthur's operation. .There was a good posibil- ity that both operations would be conducted simultaneously. In either .case, it was certain the tey would, conductb operations with their main fleet in the waters surrounded by the Mariana and Caroline

Islands and New Guinea. Under such circumstances, our force (es pecially the Navy) would have to operate in spite of inferior strength.

Strength from various, areas was to be concentrated in the area against which the enemy attack was anticipated. although areas from which the strength was taken would siffer, it was thought best to. carry out this plan in order to turn the tide of war in our favor,

It was decided the area for the decisive campAign would be in the waters surrounded by the Mariana and Caroline Islands and New Guinea.

For operational preparations, the ;'my endeavored to strengthen its: defense ard to increase its Lighting strength on the islands surrounding the anticipated battle area.

The Navy sent the main strength of its naval land based air units, mostly from the 1st Air Fleet (approximately 1,000 airplanes; 650 were immediately available), to the Mlariana Islands area. Part of these planes were sent to the Caroline Islands area. The 1st Plfobile

Fleet (main strength of the Naval surface force) was preparing for sorties-toward the Mariana area from Sulu Archipelago. While deciding on the operational plan, a discussion took place

as to what steps would be.taken if the enemy were to attack Biak

Island befor.e attacking the Mariana Islands, At the time, .strength

of our land based air units in the Mariana and Caroline areas was

insufficient for a decisive battled If part of the strength were

deployed to the Biak Island area, it would further endanger the

*f .Go'! Operation. The Navy decided tp withhold its air strength

though it meant loss of the Geelving Bay area,

Duringthe latter part of May, the enemy.launched an attack

against Biak Island. The Navy reversed itself and decided to hold

;the island. This was done after an investigation had been made on

the effect which loss of the island and its. use ty the enemy would

have on the "A-Go" Operation. The )javy immediateily sent one-hird

of -the land-hased air strength in the Central Pacific area from

Palau to the Halmahera area. Shortly. after arrival in the North-

of-Australia area, the majority of the combat, personnel in the air

units were attacked by malaria

On 1$ June, the enemy began attacking Saipan with the main force

.of its fleet. Though the defensive installations on Saipan were

constructed hastily and were incomplete, .they were stronger than

any used, before in th~e Southeastern and Central Pacific areas. The

army General Staff believed the island couldbe held and that the

enemy attack plan could be checked for a long time. However, the

actual battle situation proved the installations were inadequate to

stand up under furious enemy bombing and xval bombardment. As a

result, contrary to the expectation of the Army General Staff, Saipan

fell after a brief Engagement.

At thi.s time, the 31st Armyy commander was on his way back to

his command from a conference at Palau. Due to the enemy landings at Saipan (his headquarters) and Tinian, he flew to Guam. The Group

Commander for the northern Marianas and his subordinates fought

132 against the enemy 'accord~ing to :the prearrai ged plan.--on the first day, however, heavy casuaties resulted and the situation became critical.* Efforts of our., land a se d Navy }air units -were nv uce ssf u1 and str'ength was depleted.

To aid in the battle, ou~r lst .Mobile Fleet 'began 'moving outt from the Southern Philippines area, arriving on 19 June in the 2 aters off the We stern 'Mariana Islands,.. ttacks were carr'ied out tr th the carrier--based air units. These attacks proved to be tmsucoessfiil due to, interception by enemy air planes and anti-aircraft fiare.

Loss of the 'major portion of our carrier-based air strength antd several carriers forced the Fleet to withdraw. The £oreg6i1g was the ttA . GO" Operation.

Meanwhile,~aipan ::rmy uXits on had been 'conducting effective counterattacks, but by about the 28th, sufffered losses of the major portion of their strength,* On 5 'July, the entire unit Pas' wiped 'out and the battle of Saipan came to an end. As a result, the str'ate- gical situation in the Pacific area changed completely. Imerial General Headquarters planned to conduct an operation. to recatptuzre the Marianas but due to the inferior strength of our carrier force abandoned the idea.

The Annry General Staff emphasized the importance of the

Ogasawara Islands area due to the changed situation in the ' Niriana

Islands area. Command structure for the 31st' Army became a probl ' because, command of the Ogasawara. Islands by~ the 31st army actually" became impossible-, In the latter part. of June an order' to reorganize the Ogasawara Gr'oup under direct control of the .:,my General .Staff was issued.. It was planned to ship troops -and munitions to- tfiis unit whenever the transportation. situation permitted.

133 Instructions Strengthening Homeland Defenses

Due to the situation in the Pacific area, it became necessa.ry

to strengthen defenses of the Homeland, The Army Gneral Staff

issued necessary orders in the early part of May as a result of studies

which had been made since late January l944. Influencing the begin-

ning of these studies were the enemy actions during November 1913.

The Commander of Homeland Defenses had been responsible, for

the command of armies in the Homeland in regard to Homeland defense

only. In view of the increasing critical situation, his centralized

command authority over most of the armies was strengthened, thus ir-

proving the coordinated effort of the various Homeland Armies in training, guard and defense efforts. The eastern, Central and

Western District Armies (main ground forces in the Homeland) and the

10th (Tokro), 18th (Osaka) and 19th (Northe.?n. Ky>elu) Air Divisions

(main defensive air units) were placed under complete command of the

Commander of Homeland Defenses, The.1st Air army c o1mmander and the

Korea Army commander were also placed under him for defense operations. The 5th Area Army (Hokkaido) remained under the Chief of

Army General Staff.

Homeland defense duty assignments issued by the 'krmy General

Staff were to accomplish adequate reinforcement. The Commander of

Homeland Defenses was to cooperate with the Navy in carrying out, the military preparations. Primary objective was to repel enemy air attacks, and protect the strategic region of the Homeland, Defenses of key points along the coast of the mainland and outlying islands were to be reinforced. The Army was to cooperate with the Navy in protecting sea transportation. Effective precautionary measures against air raids were to -be developed.

Instructions issued in connection with orders stated that air defense was 'to protect the Imperial Palace and military installatons in Tokyo-Yokohama, okura-Ya iata, Nagoya and Osaka -Kobe areas. The

China Expeditionary Army, Kwantung Army, the 5th Area Srry and Formosa

134 Army commanders were to cooperate with the Commander of Homeland

Defense in maintaining communication for intelligence reports on

enemy air raids, Various strategic military positions and movements

were to be protected against enemy attacks. in effort would1 be made

to maintain public order. As a limit to his authority, the Commander

of Homeland Defenses had to obtain approval from the Chief of the

Army General Staff before changing the location of troops except in

cases of emergencies and very minor movements.

In the over-all reorgan zation, the line of communication in the

Homeland became extremely important. The supply depots in the Home-

land were unable to maintain the job of supplying materiel require.

ment abroad because it became difficult to schedule military in-

dustrial. production. This was caused by the poseibility of enemy

air raids, rapid increase in the number of troops in our Army strength,

loss of munitions while being shipped, and difficulty of trans port-

ing essential natural resources from abroad, It was planned to

disperse the munitions stored at the supply depots. This plan was

undertaken and it was speeded up after the Ilariana region was captured by the enemy. The munition plants weree not moved in order

to avoid lowering the current production rate.

The Army had mobilized strength amounting to approximately

3,650,000 by the end of March l19W.. After reviewing the; situation, it was believed this could be expanded by approximately l,QOQ,OoO.

Due to shipping difficulties, it was considered impossible t&o send troops abroad after summer, Thus, the required strength was being mobilized during the fi.rst part of the year.

Line of Communication (Logistical support) ..Durn .asT hrd

The supply of operational materiel became inadequate. At this time, thedecisive battle was beginning and shipping .bepamne .difficult due to enemy air and submarine attacks.. Shipment of supplies to strategic areas Toud be continued but it was to by reduced :tb a minimum in other areas. The quality and. quantity of munitions ad

shipping did not always fill operational needs due to the changin.g battle situation which necessitated changing troop dispositions.

The increased number of ships being lost caused our supply system

to become inadequate. As a result, each operational Army received

orders to establish a system of self-subsistence. Strength of the

line of commuication could not be employed effectively under

prevailing shipping conditions and because of deteriorating equip-

met.

136