The first ten days of August 1945 had been disastrous for Japan. Having seemingly ignored the 26 July Potsdam Declaration of Allied terms, the beaten and increasingly devastated nation's military clung to hope that the coming invasion of the home islands would be beaten back at great cost to the invaders, making possible a more favorable negotiated peace.

However, on 6 August, the Hiroshima atomic bombing demonstrated that the "prompt and utter distruction" promised by the Potsdam Declaration was now at hand. That message was reinforced by the Nagasaki bomb three days later. A fast-moving Soviet invasion of Manchuria on the same day shattered any expectation that Japan's large army could hold back her enemies' conventional forces. This triple shock prompted, after several difficult meetings of his chief officials, the Japanese Emperor's decision to end the War by accepting the Allies' terms, a decision announced on 14 August.

Eighteen days of celebrations, preparations, prisoner of war recovery and initial occupation activities by the Allies followed, initially with considerable wariness of possible Japanese treachery. Things went relatively smoothly, though, building to a dramatic climax on 2 September 1945 in Tokyo Bay, when representatives of Japan's government and her military signed the Instrument of Surrender on board USS Missouri (BB-63).