On receipt of the Japanese offer to surrender, the decision was quickly made by Harry Truman as to the US response. From his August 10, 1945 diary entry:
“Ate lunch at my desk and discussed the Jap offer to surrender which came in a couple of hours earlier. They wanted to make a condition precedent to the surrender. Our terms are ‘unconditional’. They wanted to keep the Emperor. We told ’em we’d tell ’em how to keep him, but we’d make the terms.”
Truman ordered that no more atomic bomb attacks be made, although conventional attacks be continued. When the press misinterpreted an Army Air Corps briefing that mentioned that no bombers were flying over Japan due to bad weather on August 11, 1945, Truman ordered a halt to conventional attacks so the Japanese would not be confused on his willingness to give them a short time to consider the Allied response. The response went out on August 11, the Soviets signing on reluctantly as they were busily conquering Manchuria from the Japanese and did not want the War to stop until they had wiped out Japanese opposition. Here is the text of the Allied response:
The Honorable James F. Byrnes
Secretary of State August 11, 1945
Sir: I have the honor to acknowledge receipt of your note of August 10, and in reply to inform you that the President of the United States has directed me to send you for transmission to the Japanese Government the following message on behalf of the Governments of the United States, the United Kingdom, the Union of Soviet Socialist Republics, and China:
“With regard to the Japanese Government’s message accepting the terms of the Potsdam proclamation but containing the statement, ‘with the understanding that the said declaration does not comprise any demand which prejudices the prerogatives of His Majesty as a sovereign ruler,’ our position is as follows:
“From the moment of surrender the authority of the Emperor and the Japanese Government to rule the state shall be subject to the Supreme Commander of the Allied powers who will take such steps as he deems proper to effectuate the surrender terms.
“The Emperor will be required to authorize and ensure the signature by the Government of Japan and the Japanese Imperial General Headquarters of the surrender terms necessary to carry out the provisions of the Potsdam Declaration, and shall issue his commands to all the Japanese military, naval and air authorities and to all the forces under their control wherever located to cease active operations and to surrender their arms, and to issue such other orders as the Supreme Commander may require to give effect to the surrender terms.
“Immediately upon the surrender the Japanese Government shall transport prisoners of war and civilian internees to places of safety, as directed, where they can quickly be placed aboard Allied transports.
“The ultimate form of government of Japan shall, in accordance with the Potsdam Declaration, be established by the freely expressed will of the Japanese people.
“The armed forces of the Allied Powers will remain in Japan until the purposes set forth in the Potsdam Declaration are achieved.”
Accept (etc.) James F. Byrnes Secretary of State
Mr. Max Grassli
Charge d’Affaires ad interim of Switzerland