The Interim Committee
As the Manhattan Project neared completion, there was a growing sentiment among project leaders that an advisory committee to make recommendations relating to nuclear energy should be created. In response to these concerns, in May 1945 Secretary of War Henry L. Stimson, with the approval of President Harry Truman, established the Interim Committee. The committee was so named because it was an "interim" or temporary body that would last until a more formal organization dealing with nuclear issues was created.
Although the use of the atomic bomb in World War II was not an explicit concern of the committee when it was established, the pressing matter of the Pacific war, the approaching success of the Manhattan Project, and the occupations of the Interim Committee's members inevitably led to a discussion of the issue.
- Henry Stimson (chairman), Secretary of War
- Ralph A. Bard, Under Secretary of the Navy
- Vannevar Bush, Director of the Office of Scientific Research and Development and president of the Carnegie Institution
- James F. Byrnes, former United States senator, President Truman's personal representative, and soon-to-be Secretary of State
- William L. Clayton, Assistant Secretary of State
- Karl T. Compton, Chief of the Office of Field Service in the Office of Scientific Research and Development and president of Massachusetts Institute of Technology
- James B. Conant, Chairman of the National Defense Research Committee and president of Harvard University
- George L. Harrison, assistant to Stimson and president of the New York Life Insurance Company
Initially, the committee considered targets including Kyoto, Hiroshima, Yokohama, the Kokura Arsenal, and Niigata. Kyoto and Hiroshima were considered "AA" targets because of the former's status as an "intellectual center" that would better "appreciate" the significance of the bomb and because of the latter's role as an important army depot. The idea of bombing the Japanese emperor's palace was set aside, as it was uncertain how militarily feasible this would be.
The committee also established that the bomb's power as a psychological weapon should be exploited to its fullest extent:
A. It was agreed that psychological factors in the target selection were of great importance. Two aspects of this are (1) obtaining the greatest psychological effect against Japan and (2) making the initial use sufficiently spectacular for the importance of the weapon to be internationally recognized when publicity on it is released. (emphasis ours)
B. In this respect Kyoto has the advantage of the people being more highly intelligent and hence better able to appreciate the significance of the weapon. Hiroshima has the advantage of being such a size and with possible focussing from nearby mountains that a large fraction of the city may be destroyed. The Emperor's palace in Tokyo has a greater fame than any other target but is of least strategic value.
Use of the bomb
On June 1, the committee came to a consensus regarding the bomb's use:
Mr. Byrnes recommended, and the Committee agreed, that the Secretary of War should be advised that, while recognizing that the final selection of the target was essentially a military decision, the present view of the Committee was that the bomb should be used against Japan as soon as possible; that it be used on a war plant surrounded by workers’ homes; and that it be used without prior warning. (emphasis ours)
After the committee reached this conclusion, Byrnes went to inform Truman of the outcome. The president reportedly agreed with the group's decision.
Scientific Panel recommendation
The Interim Committee was also advised by a Scientific Panel consisting of four Manhattan Project physicists: Arthur H. Compton, Enrico Fermi, Ernest Lawrence, and J. Robert Oppenheimer. On June 16, they came to their own conclusions regarding the bomb's use, opposing the findings of the Franck Report, which five days earlier had supported a demonstration of the bomb before its use.
The opinions of our scientific colleagues on the initial use of these weapons are not unanimous: they range from the proposal of a purely technical demonstration to that of the military application best designed to induce surrender. Those who advocate a purely technical demonstration would wish to outlaw the use of atomic weapons, and have feared that if we use the weapons now our position in future negotiations will be prejudiced. Others emphasize the opportunity of saving American lives by immediate military use, and believe that such use will improve the international prospects, in that they are more concerned with the prevention of war than with the elimination of this specific weapon. We find ourselves closer to these latter views; we can propose no technical demonstration likely to bring an end to the war; we see no acceptable alternative to direct military use. (emphasis ours)