Then came the successful test of the first atomic bomb.It inaugrated a new era in the world’s history and in the tools of American foreign policy.N o longer-or so it seemed-would the United States have to rely on mass armies,either those of its allies or its own.The atomic bomb had the great advantage of being cheaper than mas armies-and mach quicker. The Amerocans immediately began to use the bomb as an instrument of diplomacy.As Churchill summed up the American attitude on July 23,”It was now no longer necessary for the Russians to come into the Japanese war ; the new explosive alone was sufficient to settle the matter.”Later the same day,reporting on a conversation with Secretaty of State James Byrnes, Churchill declared,”It is quite clear that the United States do not at the present time desire Russian participation in the war against Japan .”And that evening Stimson recorded that even Marshall who had pushed hardest for Russian entry ,”felt,as I felt sure he would, that now with our new weapon we would not need the assisstance of the Russians to conquer Japan.’
At Potsdam,Truman casually informed Stalin that the United Stated had a "new weapon"and was pleased when the Soviet leader did not press him for details. The big Three then agreed to retain the Emperor after Japanese surrender but refused to let the japanese know this.Instead,they issued the Potsdam Declaration ,caling again for unconditional surrender on pain of great destruction.The Japanese rejected the demand,as it contained no guarantee on the Emperor, and Truman gave the order to drop the bomb.
在波斯坦,杜鲁门偶然告诉斯大林,美国拥有一种新式武器,而且当苏联的头领没有向他询问细节时,他还很得意。三巨头之后同意日本无条件投降后保留帝制,但拒绝让日本知道此事。鉴于此,他们发表波斯坦声明:要求(日本)无条件投降,否则将遭受大规模破坏的痛苦。日本拒绝了这个要求,因为没有保持帝制的保证。因此,杜鲁门发出了投掷炸弹的命令。