Opinions on the Bombing of Hiroshima and Nagasaki?

I still question why one must apologize for ending a war, which the imperialistic driven nation of Japan started; Especially when they had killed millions of Chinese, Filipinos, Koreans and more when they began their imperial expansion long before they attacked Pearl Harbor. Victory for the Americans does not denote we need to apologize for utilizing every mean necessary to end a war. Truman had an obligation to the American people and military. He choose to utilize a weapon that had the possibility to end the war without an invasion. There is a revisionists myth around that Japan was about to surrender. This is not true; the military was far from surrendering and were preparing their islands for a mainland invasion. The bomb ended the war and scared the hell out the Russians.