Above: The USS Arizona sinks during the bombing of Pearl Harbor

Following the surprise Japanese attack on US Navy ships in Pearl Harbor, Hawaii-- President Franklin D. Roosevelt described December 7, 1941 as “a date which will live in infamy.” Four U.S. battleships were sunk during the morning attack, and four more were severely damaged. Three cruisers, three destroyers, one minelayer, and 188 aircraft were also damaged or destroyed. But most importantly-- 2,402 Americans were killed and 1,282 wounded.

Although Japan had attacked and invaded its neighbors in Asia in the months leading up to Pearl Harbor-- President Roosevelt faced strong opposition to U.S. involvement in the war from isolationists at home. He had struggled to maintain U.S. neutrality while lending support to allies struggling against the Axis powers. The attack on Pearl Harbor aimed to cripple the U.S. Navy so that Japan’s expansion into Southeast Asia could go on unchecked. In retrospect, it had the effect of causing the Congress to finally declare war on Japan and join the Allies in World War II.

Immediately following the attack, Japan’s allies (Germany and Italy) also declared war on the United States. And so for the next four years, the United States and its Allies battled in both Asia and Europe. The battles in the Pacific against the Japanese were some of the deadliest for American forces in history. And even after Germany and Italy had fallen, Japan refused to surrender until President Harry Truman authorized the atomic bombings of Hiroshima and Nagasaki in August 1945.

The role of these actions in causing Japan's surrender and the ethical implications of atomic warfare are still debated today. Supporters generally assert that they put a final end to the war and prevented the massive casualties which would have occurred had the U.S. invaded Japan. Others who oppose the bombings argue that it was simply an extension of what was already a fierce conventional bombing campaign and was therefore unnecessary, immoral, a war crime, or a form of state terrorism. 

Nearly 400,000 U.S. soldiers died in World War II. An estimated 200,000 Japanese died in the bombings of Hiroshima and Nagasaki.