This book is a labor of love. The question of why President Truman used atomic bombs against Japan has intrigued me since I was an undergraduate history major. Indeed, it was the first issue in which the competing arguments of different scholars caught my interest, in contrast to other historiographical debates that left me befuddled and rather resentful that historians could not make up their minds and agree on revealed truth. When I attended graduate school in history, my understanding of the subjectivity of “truth” in historical interpretation and the reasons for historiographical controversy increased, as did my interest in a wide range of historical topics. At the same time, my interest in the debate over the use of the atomic bomb waned. Even though my field of specialization in graduate school was American diplomatic history, my own research focused on other matters. I thought the work of several scholars who published pathbreaking books and articles in the 1970s had largely resolved the key questions surrounding the use of the bomb.
My thinking turned out to be badly mistaken. New sources opened and new books and articles appeared with fresh things to say about Truman and the bomb. By the time of the fortieth anniversary of Hiroshima in 1985, there was an outpouring of scholar