·DOCID: 4001113 COMINT and the PRC Intervention in the Korean Wat1:S-CCO~ GUY R. VANDERPOOL Ed.it.or'• Note: (U) Thi.a ia an e:w:panded veraion of an addreaa given by Guy R. Vanderpool at the Cryptologic Hiatory Sympoaiwn in October 1993. "A RISK WE KNOWINGLY TOOK" (U) (U} On 25 October 1950; four Chinese T Communist armies suddenly attacked General Douglas MacArthur's command in the approaches to North Korea's border with the PRC. The United Nations units withdrew to defensive positions.1 When MacArthu~ resumed the march a month later, the Joint Chiefs of • .. :~)' §fi;~E~~~f!~~~ :ljb~\,~:;"::_:.~;<;··!J.~~ _y;E :·;:;· :~r:~ * r:::~· ·:: ·: ·:·L~~~~..·--~·, ....~~·' , . <j • .. asked MacArthur whether; to reduce .that .~·.;::,;.,;~~...ff _, . : ~.:.: .:.Jlf.. :a:;:~ danger, he could keep U.S. units away from the Douglaa MacArlbul" PRC boundary. MacArthur immediately denounced the idea. Any such change in his operational plan would ~ "a betrayal,. of the Korean people, "appeasement of Communist aggression," and "a tribute to international lawlessness," MacArthur declared. He lectured the JCS that "t~e entry of Chinese Communists was a risk we knowingly t.ook at the time we committed o~r forces."' · (U) Nine PRC armies overwhelmed MacArthur's forces just two days later.3 Survivors I of the first assaults saw .long columns 0£ Chinese troops moving past in the mountains t.o cut off retreat.' MacArth~r cabled the JCS that he was facing "an entirely new war.~ tB-8081 But Chinese Communist communications were not new to I I···· (b) ( 1 ) American crypt.ologists. •No one who received CO MINT product, including MacArthur's own G-2 in Tokyo, should have been surprised by the PRC intervention in the Korean War. I I I "GENUINE COMMUNISTS"? (U) (U) The U.S. first obtained COMINT on the Chinese Communists from Japan's communications during, the Second World War. The intercepts reported Communist I pproved for Release by NSA on I OP Sl!!!(ltr!ll' HIMl!ll 9-26-2012 FOIA Case# 51546 he opinions expressed in this article are those of the author(s) nd do not re resent the official o inion of NSA/CSS. ·DOCID · 4001113 CRYPTOLOGIC QUARTERLY Joint Chiefs o( Staffat Pentagon, Nove111ber 1949 Mapl I OP S!ClltET WMIUlA 2 ·DOCID: 4001113 KOREAN WAR '°' 'l!Clll!f ttMlltA mUitary operations as well e.s the position Soviet officials took when discussing the Chinese Communist Party .(CCP). For instance, Japanese ambassador Sato informed Tokyo on 4 January 1945 that Soviet foreign minister Molotov had stated during an interview: Rusaia doea not propoae to interfere ln Chineae •ft'aira and doea not support the Chinese ComrnunLtt.. It iii true that tbere is a eelf.atyled Communist Party and a Communist Army i.a China, but I peraonalJy doubt whether theee penons are genuine Communists.11 (U) Soviet leaders spoke as soothingly to American diplomats. Marshal Josef Stalin remarked to Ambassador W. Averell Harriman on 10 June 1944 that members of the Chinese Party were .. margarine Communists," and Molot.ov said essentially the same to Messrs. Donald Nelson and Patrick J. Hurley on 31 August.1 Hurley, an Oklahoma land speculator and oilman, had traveled to Moscow before taking up an assignment as President Roosevelt's personal representati~e to the Nationalist government in Chongqing. After a year in China, he still believed Molotov. Hurley announced to reporters in Washington on 28 November 1945 that he had visited Mao Zedong and Zhou Enlai at their headqua~rs in Yan'an and was convinced they weren't real Communists. "The only difference between Chinese Communists and Oklahoma Republicans is that the Oklahoma Republicans aren't armed," Hurley said.9 'Mao Zedon1 and Zhou Enlal I (U) However the Soviets depicted them and Hurley perceived them, Chinese Communists did not hide :their affiliation with Moscow. General George C. Marshall remarked to British visitors in December 1950 that he had a number of conferences with Ma1> 1.edong and Zhou Enlai in China in 1946. "Pictures of Stalin and Lenin were everywhere," and Zhou had emphasized that Chinese Communists were Marxists, not mere agrarian ref'ormers. "They regarded the Russians as co-religionists. This feeling was thoroughly indoctrinated in their troops," Marshall stated.10 3 TOP SEC:AET U"'B4 ·DOCID: 40.01113 I OP SECRE I t:IMIRA CRYPTOLOGIC QUARTERLY "A STATE OF GRAVE CIVIL CONFLICT" (U) ,,lb)(1) ./!' ~b)(3)-50 USC 403 ,.;."/ ~b)(3)-18 USC 798 (U) General Marshall's personal /;<// ~p)(3)-P.L. 86-36 encounters with CCP leaders resulted from Washington's attempt to fashion a strong, , , ' ' united, and democratic Chine. following World War U. President Truman in November 1945 named Marshall as his special envoy with the job of settling differences between the Communists and Nationalists. 11 (S:CCO) General Marshall established a framework for continued negotiations between the Communists and Nationalists, secured agreement for a cease fire, arranged for representatives of both sides to monitor the truce, and tried to mediate a permanent settlement. Before leaving Washington for Chongqing, he asked the Army's Intelligence Division to provide him COMINT support. The ~~!Jt!t!e~..;-~--~:-~~If!!!!!!•~ Army Security .Agency (ASA) was already ,: / / ~ : coHecting diplomatic and Nationalist traffic :.: ./ Georgf C. Marshall \ ', that provided commentary on China's internal situation·; and it sent: operat.ors who quickly isolated cornmunica.tions between the Communis_t:negotiators and: Yan'an. The collection\ team moved to Nanjing when the Nationalist goyernrnent and Ge~eral Marshall's ntis~ion\ transferred there in May 1946, and ASA also ~·ta~lished a new ibtercept station in seoui, ': 12 South Korell, to cover the Communist links. / / / \ ': , ' ' ' ' E'i'SS) Intercept..1------~ecE!/difficult. Unt~liable eJectrical ~we~ iii:, Nanjing and poor hearability in Seoul caused ~llection gaps.• ~ndl : I 3 General Mar!lhall was impatient. n ~SA --~--~----!!"'""!"-~""!!""'-""!""!'""!""!'------officer re lated that in June 1946 We had to go up and explain to General Marshall what [ASA Headquarteni) didn't want to put down c:m paper: I _________... 11• ('fBel Nevertheless ASA did produce cor.nNT that assisted General Marshall. -------......--- ......--------- ......-- ...fplaintext correspondence yielded over 800 translation~. A State Department official commented in the spring of 1947 that General Marshall had "a very great interest" in those messages.15 ~The diplomatic, Nationalist, and Communist communications revealed the two sides were determined to decide the future of the country by fighting rather than by T8P SEERfl' l:IMIAA 4 ·ooc1 o: 4001113 KOREAN WAR TOP Sr!eA!'f tfMIM negQtiating. In a circular message intercepted on 15 August 1946, the Communists specified why they refused to parley with the Nationalist (Kuomintang) government: ,...,,,;__m1..,.,.1l!Ofte4~ -- Pro.wte....... boW'.,,.,,. • Maci0"4W <llO•f4l • . ·_•. ...;_ , ~t"e-ICW!<f . .CA.trlta ·---.11- · .,. ... .~ 0 ' Map! 1. The Kuomintang's unwillingness to cease warfare on all fronts and its insistence I on occupying North China ~Y force. I 2. The Kuomintang's unwillingness to carry out the decision of the Political Consultative Council and its stubborn refusal to discuss political issues affecting areas which have not been occupied by force. 3. The Kuomintang's insistence on one-party government. 4. The Kuomintang's advocacy of military dictatorship. 5. The Kuomintang's failure to act on its promises.18 ~y late summer i946 it was thus evident from COMlNT t.hat China's doon5 were closed to American mediation. General Marshall bad became a powerless spectator o( the bitter struggle between Communists and Nationalists and a casualty of the Soviet· American Cold War. Washington policymakers increasingly interpreted the strife in China as a battlefield or worldwide conflict with Moscow in which confrontation rather 5 ·DOCID: 4001113 . T8P 9E8'ET YMIRA CRYPTOLOGICQUARTERL Y than negotiation was the prime consideration. While General Marshall attempted to bring the two sides together, Soviet military forces occupying Manchuria strengthened the Communists. At the same time, the U.S. provided material and financial aid to the Nationalista.17 The Communists hated the United States for helping the Chiang Kai-shek regime. They charged in their 15 August message that "the reckless actions in which the .Kuomintang has indulged and which have culminated in a state of grave civil conflict are a result of the mistaken policy of the Ameri_can authorities in giving aid to Chiang [Kai­ 8 shek)." In early 1947 General Marshall returned to Washington to be secretary of state,1 the last Communist envoys departed for Yan'an,19 and the radio links that had provide.d intelligence on the Communist negotiating position puJled oft' the air. 20 MORE THAN A MILLION REGULAR TROOPS (U) (:b)(1) (b.)(3)-50 USC 403 (b)(3}P.L. 86-36 . ·. carter W.Clarke ._~~~~~~~~~~~~~~~~~~~~~~~~~~~___. The State Department's Special Projects Staff (SPS), which was responsible for analyzing COMINT 'EQP 5i€AE'f t:IM89b\ 6 11: ·ooCID: 4001113 /:l b) KORE.ANWAR MP9EEMl•I•.# and briefing State offici4ls Qn the re~ults, completed a study of the materiai·o~ 21 A~riV 1947. ,' ' '' , ' ' ' ,, '' , ' ' ' ""tSe~or the S!>S, "nearly every message" implied "control or ~~rdinatio'1. (~·ht Moscow." The. mater~l furnished "authentic ~d ooncrete proot" of,cQoperatipn .bet.~~n Moscow and Yan'an in "propaganda and organbation" and refuted ~the repeated .deni'als of organized connections between the !CCPJ and the Soviet Governfuent." Furthe·r~r~, an 16 J4arch l946 communication in which the C~P requested ~ -'loan of "l.5 tq ; 2.~/~Uion American dolla.rs" for postwar propaganda expenses indica~ Yan'an's "depe,bden,:~e/ .. on Moscow for financial support." .· : / ./.. / . ~ E~rlier messagesb lboth de.monstrat~d t~·e pbinese ·Communists were Marxist- 11).rusts hnked closely lo the Soviet U nip'n a.IJd e<~ntained information that might ~ve profited Ameriean diplomacy and inteliigenefe o.Perations.