Firebombing Japan and the Potsdam Declaration

From early 1945 the US bombing of Japan shifted from high-altitude precision raids to low-level night attacks with incendiary bombs, under General Curtis LeMay. Japanese cities, built largely of wood, were extremely vulnerable. On the night of 9–10 March 1945, a raid on Tokyo killed an estimated 80,000 to over 100,000 people and destroyed about 40 square kilometres of the city, the deadliest single air raid in history. Dozens of other cities were firebombed in the following months.

Meanwhile, from July to August, Truman, Stalin and Churchill, replaced partway through by Clement Attlee after Britain's election, met at Potsdam near Berlin. On 26 July the US, Britain and China issued the Potsdam Declaration, demanding Japan's unconditional surrender or face 'prompt and utter destruction'. It did not mention the atomic bomb or the emperor's future. Japan's government did not accept it, while some leaders hoped the Soviet Union might mediate a better peace.