William D. Leahy

William D. Leahy was an admiral and chief of staff to Harry S. Truman. In the summer of 1945, his diary recorded a view that Japan might surrender on terms it could accept. The record makes him a significant witness to the uncertainty surrounding the end of the war: while Oppenheimer was isolated at Los Alamos, senior officials in Washington were considering whether political steps could bring the conflict to a close.

Diary and the possibility of surrender

On June 18, Leahy wrote that he believed Japan’s surrender could be arranged on acceptable terms. His entry came amid discussion in Washington about Japan’s military position and possible ways to end the war before an invasion of the home islands. The book places his judgment alongside John J. McCloy’s recommendation that Japan be told it could retain its emperor and be warned of a devastating new weapon. Leahy’s diary establishes his assessment; it does not, by itself, show that he made or controlled the government’s eventual decision.

A view recorded inside the White House

A later entry by Walter Brown, an assistant to James F. Byrnes, provides another glimpse of Leahy’s place in the deliberations. On August 3, Brown recorded that Harry S. Truman, Leahy, and Byrnes agreed that the Japanese were looking for peace. The account suggests that awareness of a possible negotiated end to the war remained present among senior officials shortly before the atomic bombs were used. It also stands in sharp contrast to Oppenheimer’s position at Los Alamos: he had not been told of the intercepted communications or of the Washington debate over surrender terms.

Significance in the account

Leahy appears here chiefly through records rather than through a developed personal portrait. His June diary entry and Brown’s August report help document that surrender through political means was considered within the administration, even as other decisions and objectives shaped policy. Together, the entries contribute to the book’s contrast between the information available to Washington officials and the limited picture presented to scientists working on the bomb. They also frame the postwar consequence for Oppenheimer: once he learned more about the wartime deliberations, he came to believe he had been misled and treated skepticism toward government assurances as an obligation.