Dresden was firebombed in February 1945, Truman became president in April 1945. The A-bomb saved a million lives. Suggest you read Unbroken about US POWs in Japan. The Japanese were prepared to fight to the last child. Look at the battles of Guadalcanal and Iwo Jima: thousands of Japanese soldiers dead to every 100 Americans. The Japanese honor code would not allow surrender. Why do you think they were so murderous toward their prisoners. Read The Rape of Nanking, too.