Not an abuse of power
By this time 400,000 american soldiers had died in the war. Over 50 million died in WW2. It had to be ended. You also seem to forget about Pearl Harbor. If this was some random thing where we dropped the bonb with no reason I'd agree with you. You make Japen seem like they were the good guys. They massacred many people in China, just to take control, and dictate the country.