The Potsdam Declaration was issued on July 26, 1945 and served as an ultimatum for Imperial Japan. Two months after the surrender of Nazi Germany, the Allies were still at war with the Empire of Japan (excluding the Soviet Union, who had not yet declared war on the country). Thus, at a conference to discuss peace settlements in Potsdam, Germany, the Allied leaders drafted a document to demand a surrender from Japan.
The Declaration was put together by American President Harry Truman, British Prime Minister Winston Churchill, and the Chairman of the National Government of the Republic of China Chiang Kai-shek. The Declaration warned Japan that the country was on the “threshold of annihilation” and that it should “follow the path of reason” to avoid such destruction. The path of reason, in the eyes of the Declaration’s authors, was to surrender unconditionally and accept the terms the Allies had laid out. The terms of surrender outlined in the declaration were for Japan to completely disarm their military, allow for some areas of the country to be occupied, and to create a new “responsible government”. The Declaration promised that the Japanese people would not be enslaved and that the nation would not be destroyed if the terms were accepted. If the terms were rejected, the Declaration promised “prompt and utter destruction”.
The Declaration was largely ignored by Japan, and the war continued. Shortly thereafter, the United States dropped atomic bombs on Hiroshima on August 6 and Nagasaki on August 9, fulfilling their promise of destruction. The Soviet Union also finally declared war on Japan, invading the Japanese-occupied Manchuria. With little hope for victory and after much destruction and death, Japan officially surrendered to the Allies on August 15, 1945.
Suggested Reading:
Atomic Heritage Fund: The Potsdam Declaration (official document)
Charles Editors, The Potsdam Conference: The History of the Negotiations Between the Allies Near the End of World War II
