On August 10, 1945, following the atomic bombing of Nagasaki and Soviet entry into the war against Japan, the Japanese government sent a message to the Allies through neutral Switzerland and Sweden accepting the Potsdam Declaration's terms, on the condition that the Emperor's sovereign position be maintained. The message set off feverish negotiations that would culminate in Japan's formal surrender five days later.
The 48 hours between the bombing of Nagasaki on August 9 and Japan's surrender message were chaotic within Tokyo's leadership. Japan's Supreme Council for the Direction of the War was deadlocked, split between military hardliners who wanted to fight on and civilian leaders who recognized the war was unwinnable. Only an unusual personal intervention by Emperor Hirohito himself, breaking centuries of imperial detachment from direct policy decisions, broke the deadlock in an overnight meeting.
In the early hours of August 10, Japan's Foreign Ministry transmitted a message via the Swiss and Swedish governments to the United States, Britain, China, and the Soviet Union, stating Japan was prepared to accept the terms of the Potsdam Declaration—provided it did not compromise the Emperor's prerogatives as sovereign ruler. This was a significant walk-back from Japan's earlier flat rejection of Potsdam's unconditional surrender demand back in late July.
Allied leaders debated the acceptable phrasing for days, eventually crafting a response that allowed the Emperor to remain but subordinated him to the Supreme Commander of Allied powers. Even after this, hardline Japanese officers attempted a coup on the night of August 14–15 to prevent surrender, seizing the Imperial Palace grounds briefly before being suppressed. Hirohito's surrender broadcast finally aired on August 15, ending the war.
Key people: Hirohito, Harry Truman