Atomic bombings of Hiroshima and Nagasaki

On 6 August 1945 an American B-29 dropped an atomic bomb on Hiroshima; three days later a second bomb destroyed Nagasaki. The two attacks killed an estimated 110,000 to 210,000 people by the end of the year, the overwhelming majority civilians, through blast, fire and radiation, and marked the first and only use of nuclear weapons in war. Between the two bombings the Soviet Union declared war on Japan and invaded Manchuria. On 15 August Japan announced its surrender, which was formally signed on 2 September aboard USS Missouri in Tokyo Bay, ending the Second World War. The bombings remain among the most debated decisions in history: their defenders argue they avoided a costly invasion of the Japanese home islands, while critics question both their necessity and their targeting of cities. Their consequences shaped the nuclear age that followed. The Potsdam Declaration of late July had demanded Japan unconditional surrender, and the Soviet entry into the war in early August removed any hope of a negotiated peace.