On July 16, 1945, the United States detonated the world's first nuclear device, the Trinity test device, at the White Sands Proving Ground, New Mexico.
On July 26, 1945, the United States, Great Britain and China issued the
Potsdam Declaration to Japan.
Quote:We-the President of the United States, the President of the National Government of the Republic of China, and the Prime Minister of Great Britain, representing the hundreds of millions of our countrymen, have conferred and agree that Japan shall be given an opportunity to end this war ...
We call upon the government of Japan to proclaim now the unconditional surrender of all Japanese armed forces, and to provide proper and adequate assurances of their good faith in such action. The alternative for Japan is prompt and utter destruction.
Japan treated the declaration with mokusatsua, a Japanese word meaning "to ignore" or "to treat with silent contempt".
Eleven days later (August 6) the United States detonated the world's second nuclear device over Hiroshima, Japan.
Three days later (August 9) the United States detonated the world's third nuclear device over Nagasaki, Japan.
Japan surrendered on August 15.