Pearl Harbor Attack: US Enters World War II

Japanese aircraft struck the U.S. naval base at Pearl Harbor, Hawaii, in two devastating waves on the morning of December 7, 1941, killing 2,403 Americans and dragging the United States into World War II. The surprise attack destroyed or damaged 21 ships and 347 aircraft in less than two hours, crippling the Pacific Fleet's battleship force. By nightfall, the isolationist debate that had paralyzed American foreign policy was over. Admiral Isoroku Yamamoto had planned the attack for months, training pilots in torpedo runs over shallow harbors that mimicked Pearl Harbor's geography. Six Japanese aircraft carriers launched 353 planes in two waves beginning at 7:48 a.m. local time. American forces were caught almost completely unprepared. Radar operators at Opana Point detected the incoming aircraft but were told to ignore the signal, which was mistaken for an expected flight of B-17 bombers arriving from the mainland. The USS Arizona exploded when a bomb penetrated its forward magazine, killing 1,177 sailors and Marines in a single blast. The ship sank in minutes and remains on the harbor floor as a memorial. The USS Oklahoma capsized, trapping hundreds of men below decks. Eight battleships were hit. But the attack missed critical targets: the base's oil storage tanks, submarine pens, and repair facilities survived intact. Most crucially, all three Pacific Fleet aircraft carriers were at sea and untouched. President Franklin Roosevelt addressed Congress the next day, calling December 7 "a date which will live in infamy." Congress declared war with only one dissenting vote. The attack unified a divided nation overnight and committed American industrial power to a global conflict. Yamamoto, who had studied at Harvard and knew American capacity intimately, reportedly told colleagues that Japan had "awakened a sleeping giant and filled him with a terrible resolve." Within four years, that resolve had ended both the European and Pacific wars.