Kyle

“(1) the commitment to ending the war successfully at the earliest possible moment; (2) the need to justify the effort and expense of building the atomic bombs; (3) the hope of achieving diplomatic gains in the growing rivalry with the Soviet Union; (4) the lack of incentives not to use atomic weapons; and (5) hatred of the Japanese and a desire for vengeance.”
― J. Samuel Walker, Prompt and Utter Destruction: Truman and the Use of Atomic Bombs against Japan, Revised Edition