President Truman felt he was justified in the use of atomic bombs. He said that it was the right thing to do on the grounds that doing so saved many lives. In a radio address he gave prior to Japan's final surrender, he said that the use of atomic weapons was chosen "in order to shorten the agony of war, in order to save the lives of thousands and thousands of young Americans."
However, notice that Truman's rationale was about the loss of life by American soldiers if a war on the ground were pursued in Japan. He did not as much take into account Japanese lives, though many Japanese soldiers would also have lost their lives in conventional warfare if that were pursued. And the atomic bombs killed an estimated 150,000 persons in Hiroshima and an estimated 75,000 persons in Nagasaki in a very short time. Added to that were all sorts of severe, negative health effects that contributed to sickness and early death to many more people due to radiation from the bombs. So, many have questioned the ethics of using atomic bombs rather than seeking other alternatives for ending the war.
