In 1941, President Franklin D. Roosevelt with the consent of the US secret atomic bomb development program, known as the Manhattan Project and later taken over by the War Department. Due to highly confidential plan, people know Washington D.C. is extremely rare at that time. In 1944, U.K. Prime Minister Winston Churchill and Roosevelt decided to use the atomic bomb against Japan. April 12, 1945 Roosevelt died, Harry S. Truman took over as President. After Secretary of War Stimson to brief him on April 27, Truman learned the atomic bomb project.
May 7, Third Reich surrendered, ending the war in Europe. Truman immediately faced with a difficult choice, as soon as possible to end the war with Japan. US strategic bombing almost defeated Japan, their domestic economy and combat capability has been destroyed and exhausted, but still reluctant to surrender. US military chiefs estimate based on the experience of the Pacific war, if landed in Japan, the US military will be costly. The US military complex and overlapping in the Pacific combat command structure, and confusion of battle plans, not only to unified strategy against Japan, when it can defeated Japan and end the war , is still remain elusive.
Then on the eve of the Potsdam Conference, July 16, atomic bomb test is successful, designed for the transformation of the bombing of USAAF B-29 has been deployed. In Truman agreed, Secretary of War Stimson ordered the bombing of Japan . The first atomic bomb was dropped on Hiroshima on August 6, August 9 a second atomic bomb dropped on Nagasaki. On August 14, Japan announced its acceptance of the Potsdam Declaration to surrender conditions , World War II officially ended.
In this paper, Graham Allison’s three decision analysis model to in the analysis of the Cuban Missile Crisis is used, namely the rational model, organizational model and government political model, as approaches of research, to analysis the decision making process of United States dropped the atomic bomb at World War II.
This paper’s objective is to investigate Truman decided to use the atomic bomb against Japan ''s decision-making process. With decision theory’s research framework, understanding how the President to conduct major military decisions during the war, the considerations, government and military organizations’ role, and the president made the decision after thinking how the overall situation.
The paper’s point is, Truman’s primary objective is to defeat Japan when he took office, the fast end of the Pacific war. He was able consider all policy options, although the War Department, and the Department of the Navy, and the Army, Navy and Army Air Force, and other military commander will appreciate that they consider viable military option, but also the State Department on the postwar international order, against the Soviet Union and other angles to provide advice to President. But Truman integrated consideration needs all political, diplomatic, military, and finally he decided to use the atomic bomb, in order to achieve the purposes: prompt Japan''s surrender, the war ended quickly, and reduce the cost of war and casualties.
This paper argues that the Truman''s main purpose of the atomic bomb is military use, its purpose in the war against Japan as soon as possible, to restore peace and order ; The factor to influence the decision, the most important task of the government responsible for the organization is the War Department, the most important role of the staff is Stimson . To achieve the target, Truman need to convince their governments in various military and political officials , and decide to throw the bomb at the end.