In the final days of World War Two, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki in the only use of atomic weapons in the history of warfare. The war in Europe was over, but the Pacific war continued as the Allies prepared for a large-scale invasion of the Japanese mainland. After the Japanese Empire refused to surrender, the decision was made to drop atomic bombs on the 6th and 9th of August, respectively.
The explosions killed 39,000 – 80,000 people in Nagasaki and 90,000 – 166,000 in Hiroshima. Japan announced their intention to surrender on 15 August 1945 and the Allies no longer needed to launch a costly invasion of the mainland. The justification for use of atomic weapons has been debated ever since.