Did the military situation justify a surprise attack with the atom bomb?

By early in 1945 Germany had surrendered and the United States was able to focus on the war in the Pacific. Japan was suffering from a serious lack of oil and was having trouble producing more armaments with which to fight. America had a strong position in the Pacific and was moving ever closer to Japan by the time Germany surrendered.
In the February of 1944 Admiral Chester Nimitz had already been successful in a series of victories, which broke the outer perimeter of the Japanese Empire. The American submarines were taking their toll on Japanese shipping and by the summer of 1944 Japa…