What Allied ultimatum did Japan accept when it surrendered in August 1945?

Japan accepted the Potsdam Declaration when it surrendered in August 1945.

The declaration was issued on 26 July 1945 by the United States, the United Kingdom, and China during the Potsdam Conference. It demanded the unconditional surrender of Japan’s armed forces and warned that refusal would bring “prompt and utter destruction.”

Its terms called for the elimination of militarist influence, the occupation of territory designated by the Allies, disarmament of Japanese forces, and limitation of Japanese sovereignty. The declaration did not explicitly settle the future status of the emperor, an omission that contributed to uncertainty in Japan’s leadership.

Japan initially did not accept the ultimatum. The atomic bombings of Hiroshima and Nagasaki, along with the Soviet declaration of war and invasion of Manchuria, changed the strategic situation. Hirohito then supported acceptance, and Japan notified the Allies on 14 August before the public announcement on 15 August.

The Potsdam Declaration should not be confused with the Cairo Declaration, which outlined earlier Allied goals for territories taken by Japan.