Truman's Countdown to Kyushu: Reassessing Pacific War Data and Decisions (February-August 1945)

Abstract

Wars end in a variety of ways. One of these is war termination resulting from one adversary’s use of superior force to induce or compel surrender. Among all the cases of war termination by such means, one stands out and is the focus of this thesis: the Allied use of force against Japan to end the Pacific War. The decision to drop the bombs, made by President Harry S. Truman in the spring and summer of 1945, was justified by Truman at the time on the basis of a set of claims about Japanese capacity and will to pursue the war. Japan’s capacity and will were such, Truman stated in addressing the American people, that unleashing the atom bombs on two Japanese cities was America’s only recourse to avoid prolonging the war, which if continued would lead to unacceptable losses of life, both for the U.S. and for Japan. Truman’s claims about Japan’s fighting capacity and will have long been disputed. Some have argued that Truman exaggerated Japanese capacity and will; others have embraced his rationale, even as they have deplored the use of the bombs themselves. Much of the information and analysis that formed the basis for Truman’s claims at the time, in the spring and summer of 1945, about Japanese capacity and will to pursue the war are not fully known. However, now it is possible to assess such claims retrospectively using a data source digitally published in 2014: The Gray Book, a 4,000-page compilation of granular data collected by the U.S. military on Japanese troop, sea and air actions, from December 1941 until August 1945. Before 2014, data in The Gray Book were too difficult for outside parties to access to be easily analyzable to verify the aggregated recommendations of Truman’s advisors; however, recently, they are digitized and available, making finer analysis possible. This retrospective examination concludes that the data generally support Truman’s claims about Japanese will and capacity. Granular analysis supports his arguments that, despite U.S. military forces pushing the Japanese expansionist front lines back 4000 miles in the years 1942 to 1945, levels of Japanese fighting will and resistance were high as of June of 1945 and were increasing as U.S. troops neared the Japanese main islands.