The Pearl Harbor Raid Revisited Alvin D. Coox San Diego State University

The distinction between deterrence and incitement is a fine one. In May 1940, by directing that the Pacific Fleet be based at "impregnable" Pearl Harbor rather than on the American West Coast, President Franklin D. Roosevelt unwittingly sealed the fate of America's battle- ship force, the pride of the U.S. Navy. Long-range historical conse- quences were to prove even more decisive.'I At that time, the key to Japanese naval thinking lay with Admiral Yamamoto Isoroku, who had taken command of the Combined Fleet late in August 1939. His hand could be felt in new emphasis on air combat, training, unorthodox conceptions of battle, and early deci- sions. Reacting to the presence of the Pacific Fleet at Pearl Harbor, Yamamoto advised the Naval High Command that, strategically speak- ing, the situation was "tantamount to a dagger pointed at our throat." But, Yamamoto added, America's naval threat to Japan could become Japan's threat to America.2 Japanese naval policy regarding the United States, its major hypo- thetical naval enemy, had long been essentially defensive in the strate- gic sense. By 1940, it was anticipated that in the event of war the American battle fleet would promptly steam west from Hawaii and engage the (IJN) in decisive combat north of the Marshalls and east of the Marianas. The question of Japanese ini- tiative, however, remained troublesome. Destruction of the Americans' Asiatic Fleet, conquest of their possessions in East Asia, and disrup- tion of maritime trade could exert only indirect effects on the enemy. The most revolutionary Japanese scheme to provoke the American fleet into action was to consider developing giant flying boats capable

The Journal of American-East Asian Relations, Vol. 3, No. 3 (Fall 1994) @ Copyright 1994 by Imprint Publications, Inc. All rights reserved. 1. Naval History Division, On the Treadmill to Pearl Harbor: the Memoirs of Admiral James O. Richardson as told to Vice Admiral George C. Dyer (Washington, D.C., 1973), chaps. 19-20; Samuel Eliot Morison, The Rising Sun in the Pacific,1931-April 1942 (Boston, 1948), 42�3; Homer N. Wallin, Pearl Harbor: Why, How, Fleet Salvage and Final Appraisal (Wash- ington, D.C., 1968), 41-43; Gordon W. Prange with Donald M. Goldstein and Katherine V. Dillon, Pearl Harbor: the Verdict of History (New York, 1986), 119-20. 2. Fukudome Shigeru, "Hawaii Operation," in Paul SHllwell, ed., Air Raid: Pearl Har- bor! Recollections of a Day of Infamy (Annapolis, Md., 1981), 62-63. of traveling fifty-five hundred miles with a four-ton bomb load. They would strike Pearl Harbor from the Marshall Islands, and that, pre- sumably, would prompt American admirals to order their fleet to sor- tie. But that project never bore fruit. Japanese admirals continued to think in terms of grand sea battles, and even their war games degen- erated into a war of attrition-something unacceptable to their quan- titatively inferior fleet.3 The first realistic idea for an unconventional attack against the American Pacific Fleet at Pearl Harbor arose in Yamamoto's mind af- ter successful IJN fleet exercises in the spring of 1940. The admiral was particularly pleased by the progress of aerial torpedo assault tac- tics against forces. While his colleagues could conceive only of submarine action and massive surface combat against targets in Hawaiian waters, Yamamoto was already thinking about decisive at- tack from the air. He felt that major operations against mainland bases were out of the question; but attacks on targets further west were not. The impetus for Japan to rethink its situation came after the stun- ning German successes in May and June 1940, which produced a reor- dering of international forces that gave the appearance of a power vacuum east of the Suez. Were Japan to grasp the resources of South- east Asia and take the Philippines hostage, urgent consideration would have to be given to the nature and speed of an American reaction. After evaluating map maneuvers in November 1940, Yamamoto con- cluded that the oil-rich Dutch East Indies could not be subdued with- out provoking the United States and Britain into war. What would happen if the Pacific fleet counterattacked while the main body of the Combined Fleet was deployed in the south?4 By early January 1941 Yamamoto found an answer to that question. He recommended to the Navy minister that, in the unhappy event of war with the United States, Japan strive to cripple the Americans' main battle fleet in the Pacific by an air offensive launched concurrently with a campaign in Southeast Asia. The benefits would be manifold: Enemy morale, both civilian and military, would be damaged, per- haps to the point of rendering the Americans helpless. The American fleet would be kept from threatening the exposed Japanese flank and from unleashing psychologically disturbing air strikes against cities in the Japanese homeland. From what he knew of Pacific Fleet Com-

3. Carl Boyd, "Japanese Military Effectiveness: the Interwar Period," in Williamson Murray and Allan R. Millett, eds., Calculations: Net Assessment and the Coming of World War 11, vol. 2, The Interwar Period (New York, 1992), 144; author's interviews with Takai Mitsuo, July 14 1984, 27 July 1985, and August 23 1986. 4. Agawa Hiroyuki, The Reluctant Admiral: Yamamoto and the Imperial Navy, trans. John Bester (Tokyo, 1982), 193-94.