The 7 December 1941 Japanese raid on Pearl Harbor was one of the great defining moments in history. A single carefully-planned and well-executed stroke removed the United States Navy's battleship force as a possible threat to the Japanese Empire's southward expansion. America, unprepared and now considerably weakened, was abruptly brought into the Second World War as a full combatant.
Eighteen months earlier, President Franklin D. Roosevelt had transferred the United States Fleet to Pearl Harbor as a presumed deterrent to Japanese aggression. The Japanese military, deeply engaged in the seemingly endless war it had started against China in mid-1937, badly needed oil and other raw materials. Commercial access to these was gradually curtailed as the conquests continued. In July 1941 the Western powers effectively halted trade with Japan. From then on, as the desperate Japanese schemed to seize the oil and mineral-rich East Indies and Southeast Asia, a Pacific war was virtually inevitable.
By late November 1941, with peace negotiations clearly approaching an end, informed U.S. officials (and they were well-informed, they believed, through an ability to read Japan's diplomatic codes) fully expected a Japanese attack into the Indies, Malaya and probably the Philippines. Completely unanticipated was the prospect that Japan would attack east, as well.
The Pearl Harbor naval base was recognized by both the Japanese and the United States Navies as a potential target for hostile carrier air power. The U.S. Navy had even explored the issue during some of its interwar "Fleet Problems". However, its distance from Japan and shallow harbor, the certainty that Japan's navy would have many other pressing needs for its aircraft carriers in the event of war, and a belief that intelligence would provide warning persuaded senior U.S. officers that the prospect of an attack on Pearl Harbor could be safely discounted.
During the interwar period, the Japanese had reached similar conclusions. However, their pressing need for secure flanks during the planned offensive into Southeast Asia and the East Indies spurred the dynamic commander of the Japanese Combined Fleet, Admiral Isoroku Yamamoto to revisit the issue. His staff found that the assault was feasible, given the greater capabilities of newer aircraft types, modifications to aerial torpedoes, a high level of communications security and a reasonable level of good luck. Japan's feelings of desperation helped Yamamoto persuade the Naval high command and Government to undertake the venture should war become inevitable, as appeared increasingly likely during October and November 1941.
All six of Japan's first-line aircraft carriers, Akagi, Kaga, Soryu, Hiryu, Shokaku and Zuikaku, were assigned to the mission. With over 420 embarked planes, these ships constituted by far the most powerful carrier task force ever assembled. Vice Admiral Chuichi Nagumo, an experienced, cautious officer, would command the operation. His Pearl Harbor Striking Force also included fast battleships, cruisers and destroyers, with tankers to fuel the ships during their passage across the Pacific. An Advance Expeditionary Force of large submarines, five of them carrying midget submarines, was sent to scout around Hawaii, dispatch the midgets into Pearl Harbor to attack ships there, and torpedo American warships that might escape to sea.
Under the greatest secrecy, Nagumo took his ships to sea on 26 November 1941, with orders to abort the mission if he was discovered, or should diplomacy work an unanticipated miracle. Before dawn on the 7th of December, undiscovered and with diplomatic prospects firmly at an end, the Pearl Harbor Striking Force was less than three-hundred miles north of Pearl Harbor. A first attack wave of over 180 aircraft, including torpedo planes, high-level bombers, dive bombers and fighters, was launched in the darkness and flew off to the south. When first group had taken off, a second attack wave of similar size, but with more dive bombers and no torpedo planes, was brought up from the carriers' hangar decks and sent off into the emerging morning light. Near Oahu's southern shore, the five midget submarines had already cast loose from their "mother" subs and were trying to make their way into Pearl Harbor's narrow entrance channel.
Japanese planes hit just before 8AM on 7 December. Within a short time five of eight battleships at Pearl Harbor were sunk or sinking, with the rest damaged. Several other ships and most Hawaii-based combat planes were also knocked out and over 2400 Americans were dead. Soon after, Japanese planes eliminated much of the American air force in the Philippines, and a Japanese Army was ashore in Malaya.
These great Japanese successes, achieved without prior diplomatic formalities, shocked and enraged the previously divided American people into a level of purposeful unity hardly seen before or since. For the next five months, until the Battle of the Coral Sea in early May, Japan's far-reaching offensives proceeded untroubled by fruitful opposition. American and Allied morale suffered accordingly. Under normal political circumstances, an accommodation might have been considered.
However, the memory of the "sneak attack" on Pearl Harbor fueled a determination to fight on. Once the Battle of Midway in early June 1942 had eliminated much of Japan's striking power, that same memory stoked a relentless war to reverse her conquests and remove her, and her German and Italian allies, as future threats to World peace.
Jhesu + Marie,
*A nearly vertical view of Ford Island and the East Loch. This view shows 8 battleships and an aircraft carrier possibly the USS Saratoga or the Lexington (judging by the size of the aircraft carrier's superstructure). The battleships are in the possition they would be in during the raid 19 months later. This view also shows the airfield which maintained seaplanes and the aircraft groups (CAG) assigned to the carriers which were landed when the carriers were in port. The other ships including the battle groups escorts; cruisers, destoyers and refuelers.
Naval Historical Command