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Attack on Pearl Harbor



The attack on Pearl Harbor was a pre-emptive military strike on the United States Pacific Fleet base at Pearl Harbor, Hawaii by the Empire of Japan's Imperial Japanese Navy, on the morning of Sunday, December 7, 1941 that made the United States enter World War II. Two aerial attack waves, totaling 350 aircraft, were launched from six aircraft carriers with the intent to destroy the United States Pacific Fleet.






The attack wrecked two U.S. Navy battleships, one minelayer, and two destroyers beyond repair, and destroyed and 188 aircraft; personnel losses were 2,333 killed and 1,139 wounded. Damaged warships included three cruisers, a destroyer, and six battleships (one deliberately grounded, later refloated and repaired; two sunk at their berths, later raised, repaired, and restored to Fleet service late in the war). Vital fuel storage, shipyards, and submarine facilities were not hit. Japanese losses were minimal, at 29 aircraft and five midget submarines, with 65 servicemen killed or wounded.






The intent of the strike was to protect Imperial Japan's advance into Malaya and the Dutch East Indies – for their natural resources such as oil and rubber – by neutralizing the U.S. Pacific Fleet. Both the U.S. and Japan had long-standing contingency plans for war in the Pacific, continuously updated as tension between the two countries steadily increased during the 1930s. Japan's expansion into Manchuria and French Indochina were greeted with steadily increasing levels of embargoes and sanctions by the United States and others. In 1940, under the Export Control Act, the U.S. halted shipments of airplanes, parts, machine tools, and aviation gas, which Japan saw as an unfriendly act.[4] Nevertheless, the U.S. continued to export oil to Japan, in part because it was understood in Washington cutting off oil exports would be an extreme step, given Japanese dependence on US oil exports, likely to be taken as a provocation by Japan.




In the summer of 1941, after Japanese expansion into French Indochina, the U.S. ceased oil exports to Japan, in part because American restrictions on internal oil use were beginning. President Franklin D. Roosevelt had earlier moved the Pacific Fleet to Hawaii and ordered a buildup in the Philippines, hoping to deter Japanese aggression in the Far East. The Japanese high command was (mistakenly) certain an attack on the United Kingdom's colonies would inevitably bring the U.S. into the war, so a pre-emptive strike appeared to be the only way Japan could avoid U.S. interference in the Pacific.






The attack was one of the most important engagements of World War II. Occurring as it did before a formal declaration of war, it pushed U.S. public opinion from isolationism to an acceptance war was unavoidable, as Roosevelt called December 7, 1941 "… a date which will live in infamy."






hough the attack was notable for its large-scale destruction, the attack was not significant in terms of American fuel storage, maintenance and intelligence capabilities. Had Japan destroyed the American carriers, the U.S. would have sustained significant damage to the Pacific Fleet's ability to conduct offensive operations for a year or so (given no diversions from the Atlantic Fleet). As it was, the elimination of the battleships left the U.S. Navy with no choice but to place its faith in aircraft carriers and submarines—the very weapons with which the U.S. Navy halted and eventually reversed the Japanese advance. A major flaw of Japanese strategic thinking was a belief the ultimate Pacific battle would be between battleships of both sides, in keeping with the doctrine of Captain Alfred Mahan. As a result, Yamamoto (and his successors) hoarded his battleships for a "decisive battle" that never happened.




Ultimately, targets not on Genda's list, such as the Submarine Base and the old Headquarters Building, were more important than any battleship. It was submarines that immobilized IJN's heavy ships and brought Japan's economy to a standstill by crippling transportation of oil and raw materials. And in the basement of the old Administration Building was the cryptanalytic unit, HYPO, which contributed significantly to the Midway ambush and the Submarine Force's success.





ear Admiral Alfred Thayer Mahan (September 27, 1840December 1, 1914) was a United States Navy officer, geostrategist, and educator. His ideas on the importance of sea power influenced navies around the world, and helped prompt naval buildups before World War I. Several ships were named USS Mahan, including the lead vessel of a class of destroyers. His research into naval History led to his most important work, The Influence of Seapower Upon History,1660-1783, published in 1890.


Mahan was translated and extensively read in Japan,[4] and the Imperial Japanese Navy (IJN) used Influence as a textbook. This strongly affected IJN conduct in the Pacific War, with emphasis on "decisive battle", even at the expense of trade protection. Ironically, Mahan's premise that a reserve force being incapable to recover after initial overwhelming defeat was refuted by the US Navy's own recovery after Pearl Harbor. The IJN pursuit of the "decisive battle" was carried out to such an extent that it contributed to Japan's defeat in 1945.[5][6] And Mahanian doctrine of a decisive battle fought between fleets of battleships became obsolete by the development of submarines and aircraft carriers.[7]


Biographical Data On Rear Admiral Alfred Thayer Mahan



Pearl Harbor Newsletter

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