At 5 hours 30 minutes AM on July 16, 1945 the United States tested an atomic bomb in the desert of Alamogordo in New Mexico. The test was a triumphant success. The explosion was stronger than expected - it was an explosion equivalent to about 20 kilotons of trinitrotoluol (Rhodes, 1986).
The US President Harry S. Truman was to decide what US policy should be carried out toward nuclear bomb (Bernstein, 1975). Truman knew nothing about the bomb until he became the president, and he was informed about it by Henry L. Stimson, the US Secretary of Defense, and by the President’s friend James F. Byrnes, a Roosevelt’s adviser. Byrnes, whom Truman soon appointed the Secretary of State, told him that the bomb “can be so powerful that it has the potential to burn entire towns to the ground and to destroy people on an unprecedented scale.” Byrnes believed that “at the end of the war the bomb could allow the Americans to dictate the world their own terms.” (Truman, p.104)
The Americans were convinced that Russians weren’t aware of the atomic bomb creation. How do they know? After all, when in April, 1945 at the Potsdam conference, Harry Truman told Winston Churchill about the first successful testing of the atomic bomb, even the British prime minister was taken aback and called it a “second coming” (Stimson, 1945).
And then a triumphant Truman who, unlike his predecessor Roosevelt, weren’t experiencing any sympathy to the Soviet Union, decided to blindside Stalin. Truman hinted that the Americans now possess a powerful new weapon that will be very helpful to quickly end the war with Japan (Truman, p.458). Generalissimo, according to some Russian (Trukhanovskiy, p.23) and foreign sources (Eden, p.635), answered briefly, “I’m glad to hear that.”
Both Truman and Churchill in the conversation between them decided that Stalin did not understand them (Feis, p.102). But there is every reason to believe that he understood and properly calculated everything. He called academician Kurchatov almost immediately after the conference, ordering him to accelerate the working process on the Soviet atomic bomb. Stalin was well informed by the Soviet intelligence about the Americans secret work in the laboratory at Los Alamos, and, very likely, about a successful testing of the bomb. Therefore, in a conversation with the US president Stalin portrayed indifference, outsmarting the American (Zhukov, p.334).
But not everyone in the American president’s circle had a positive attitude to the testing and further military use of the atomic bomb. One of those opponents was Niels Bohr. He believed that the bomb opens up the possibility of a new approach to international relations, since, because of the danger of the arms race, there will be the need for cooperation. According to Bohr, the United States and the Great Britain had to inform the Soviet Union about the "Manhattan Project" before the bomb would become a fait accompli, and before the war would end. Only in this way it was possible to convince Stalin of the need for international control of the nuclear energy and of the absence of a conspiracy between the United States and the Great Britain against the Soviet Union (Bohr, p. 342-346).
The Nobel laureate in Physics, James Franco, in his report at the meeting of the Interim Committee established by Truman, also emphasized the danger of the arms race, and was against the bombs use in Japan. He was for non-military demonstration of the bombs before the representatives of the United Nations, and the use of the bombs against Japan only with the consent of the UN (Smiths, pp.560-572). But the members of the Committee rejected the proposal of the demonstration of bombs, and on June, 21, the Interim Committee endorsed the recommendation regarding the use of the bombs as soon as possible (Hewlett, Anderson, Jr., p.369).
In the 1960s there were three possible interpretations of this event among scientists. The first is that the position of Japan in 1945 was catastrophically hopeless. Second - Japanese leaders knew this and wanted to surrender in the summer of 1945. Third - thanks to decrypted messages of Japanese diplomats, the US knew that Japan was going to surrender, and she knew this when started senseless nuclear destruction. Scientists’ opinions differ on what exactly influenced the decision to drop the bomb, despite the approaching surrender; among the most daring arguments is Washington's desire to scare the Kremlin. The proposed interpretation has changed the traditionalist view in a significant layer of American society and even more – abroad (Theweeklystandart.com).
Harry Truman's grandson Clifton Truman Daniel in an interview to «Russia Today», the Russian news media, said his grandfather believed he had made the right decision to drop bombs on the Japanese cities, but did not plan to use nuclear weapons again. According to Daniel, his grandfather always thought over his decisions, and this one was not the exception. He made this decision to save the lives of Americans and to end the war (RT Documentary).
It is also interesting to hear the opinion of Theodore Van Kirk, known as "The Dutchman" - a navigator of «Enola Gay» aircraft that dropped an atomic bomb on Hiroshima. In an interview to the «Russia Today» he said that «he regrets they dropped the bomb, but they had to do it to end the war» (RT.com).
I can’t know for sure what influenced the decision of the US President, whether it was intentional or not, but given the above, I think that, first of all, he wanted to surprise and outsmart his main political opponent - Stalin. Among the possible reasons as well - a soon end of the war and approval of the US role as a world leader for the next ten years. I do not support the decision of the American president, and I think it was totally wrong since it led to disastrous consequences.
Bernstein B. J. Roosevelt, Truman and the Atomic Bomb, 1941-1945: A Reinterpretation// Political Science Quarterly. 1975. № 1. P. 34 ff.
Rhodes R. The Making of the Atomic Bomb. N. Y.: Simon and Schuster, 1986. P. 617-678.
Truman H. Memoirs. V.I: 1945, Year of Decisions. N. Y.: Signet Books, 1965. P. 458.
Stimson H. L. Diary. July 21, 1945. Yale University.
Trukhanovskiy, V. G. English Nuclear Weapon. М.: Mezhdunarodnye otnosheniia, 1985. p. 23.
Eden A. The Reckoning. Boston: Houghton Mifflin, 1965. P. 635.
Feis H. The Atomic Bomb and the End of World War II. Princeton: Princeton University Press, 1971. P. 102
Zhukov G. K. Memories and thoughts. 10 pub. М.: Novosti, 1990. Book 3. p. 334.
Bohr A. The War Years and the Prospects Raised by the Atomic Weapons// Niels Bohr/ Ed. S. Rozental. Amsterdam: p. 342-346.
Smith А. К. A Peril and a Hope: The Scientists' Movement in America, 1945— 1947. Chicago; London: University of Chicago Press, 1965. P. 41-52. (the report is on p. 560-572)
Hewlett R. G., Anderson, Jr. О. Е. The New World: A History of the United States Atomic Energy Commission. V. 1: 1939-1946. Berkeley: University of California Press, 1990. P. 369.
Richard B. Frank, 2005, Why Truman Dropped the Bomb, in Theweeklystandart.com. Retrieved from http://www.weeklystandard.com/article/7093
RT Documentary. (2015, August 8). [Exclusive interview with Clifton Truman Daniel, the grandson of President Truman]. Retrieved from https://www.youtube.com/watch?v=nYwZAS5SPik
RT.COM. (2010, August 6). ['I'd drop atomic bomb on Hiroshima again if needed' - Enola Gay last living member]. Retrieved from https://www.youtube.com/watch?v=MDaiQ9n5wEM