Hiroshima Nagasaki

The atomic bombings of Hiroshima (August 6, 1945, Little Boy uranium bomb, 15 kilotons) and Nagasaki (August 9, 1945, Fat Man plutonium bomb, 21 kilotons) killed an estimated 130,000-226,000 people — primarily civilians. They remain the only wartime use of nuclear weapons in history. Japan surrendered on August 15, 1945. The decision to use the bombs was controversial then and remains so — proponents argue it prevented a land invasion of Japan (projected: 500,000-1 million American and millions of Japanese casualties); critics argue Japan was close to surrender, that Soviet entry into the war on August 8 was more decisive, and that targeting civilians was immoral regardless of military justification. The bombs' legacy shaped all subsequent international relations — the nuclear deterrence doctrine, arms control treaties, and the concept of MAD (Mutually Assured Destruction).