Those in favour of the decision argued that the bombings would end the war much sooner than otherwise would have been the case, saving the lives of many allied servicemen, especially in the planned invasion of Japan. Japan was determined to fight to the end. The early end to the war also saved the lives of those in territories occupied by Japan where forced labourers had a death rate of 80%.
Opponents of the bombing said that it was inherently immoral because it would lead to the deaths of civillians and would begin an arms race. The classed it as a war crime. They also argued that victory over Japan was a foregone conclusion, especially once Russia declared war against Japan. Military leaders like Generals Eisehower and MacArthur advised against it.
If you were the President of the United States in August of 1945, would you order the atomic bomb to be dropped on Japan?
I don't know what I would have done