Japan Attacks Pearl Harbor and the United States Enters the War

In the early morning of December 7, 1941, an aerial strike force launched from six Japanese aircraft carriers targeted the United States Pacific Fleet stationed at Pearl Harbor on Oahu, Hawaii. Begun just before 8 a.m. local time, the two-wave raid involved more than 350 aircraft, including torpedo bombers, dive bombers, and fighters. The sudden offensive struck eight American battleships, damaging all of them and sinking four, while destroying over 180 military aircraft on nearby airfields. The operation killed more than 2,400 Americans and left nearly 1,200 wounded, delivering an immense shock to a country that was then officially neutral.

The assault represented the culmination of years of worsening relations over territory and resources in East Asia. Following Japan's invasion of Manchuria in 1931 and the outbreak of the Second Sino-Japanese War in 1937, the United States progressively restricted shipments of strategic materials to Tokyo. Tensions peaked in July 1941 when Washington halted oil exports after Japanese forces expanded into French Indochina. Lacking domestic petroleum supplies to sustain its military campaigns, Tokyo prepared to seize the resource-rich territories of the Dutch East Indies and British Southeast Asia. Japanese military leaders, subscribing to doctrines emphasizing decisive naval battles, concluded that a pre-emptive blow against the Pacific Fleet was essential to prevent American naval intervention.