At 0600 on the morning of Dec. 7, 1941, Lieutenant Mitsuo Matsuzaki lifted off in his Nakajima B5N2 torpedo bomber from Akagi, one of six Japanese aircraft carriers sailing in loose formation some 230 miles north of Hawaii. Just under two hours later the man sitting behind Matsuzaki, Commander Mitsuo Fujita, slid back his section of the plane’s canopy and fired a green flare—a signal to the 182 other aircraft of the first assault wave to begin Japan’s surprise attack on the U.S. Pacific Fleet at Pearl Harbor. The flare also marked the start of a war Japan had no hope of winning. The 1941–45 war between Japan and the United States seems, in retrospect, inevitable.
By 1941 Japan, which had subdued much of China, was determined to conquer all of East Asia, including mineral-rich, Western-colonized Southeast Asia. Japan’s imperial ambitions in East Asia inexorably collided with Western interests in the region, and Japan’s 1940 military alliance with Nazi Germany, though of little operational significance, further alienated the Western powers. The United States was preoccupied with events in Europe, especially Britain’s survival, which depended significantly on continued access to imperial manpower and other resources worldwide. But Washington was not prepared to accept Southeast Asia’s subjugation by Japan. Certainly any Japanese attack in the region that included an invasion of the Philippines would mean war. The islands were a strategic liability, but they were still an American colony garrisoned by U.S. military forces.