What happened
The war opened on December 7–8, 1941, with the attack on Pearl Harbor and simultaneous offensives across Southeast Asia; within six months Japan had taken Singapore and the Philippines. The tide turned at Midway (June 1942, four carriers lost) and Guadalcanal (1942–43). Saipan (1944) brought B-29s within range of Japan, and Leyte Gulf (October 1944), the largest naval battle in history, saw the first organized kamikaze attacks.
Firebombing devastated Japanese cities — the Tokyo raid of March 9–10, 1945 killed roughly 100,000 in one night — and Okinawa (1945) cost some 200,000 lives, including a huge civilian toll. Atomic bombs struck Hiroshima (August 6) and Nagasaki (August 9); the Soviet Union entered the war on August 8–9. Surrender was announced on August 15 and signed on September 2, 1945.
Background
The Pacific War was fought between Japan and the Allies as part of World War II.
Consequences
Japan’s war dead are commonly put at around three million; the war Japan waged caused far greater losses across Asia. Defeat brought the occupation, the 1947 constitution, and the postwar order.