The first bomb(s) dropped would certainly have been on Germany for the exact same reason we dropped them on Japan…the shorten the war and save American lives. Racial hatred, if it came in at all, would have been running a far distant third in our reasons for dropping it…first and second being save American lives/shorten the war, and save money.
Ok, so, we drop the first bomb on Hamburg or Dresden (possibly Berlin but I doubt it) as a demonstration of our power. I’m fairly sure that even if Hitler was wacked enough to want to go on the military would have been forced to step in at that point and take control if necessary to end the war. I doubt we’d have had to drop a second bomb like we did in Japan.
My questions would be…what would the Soviets have done? If Germany suddenly surrendered to the US, would the Soviets allow the remnants of the Germany armies in their territory to surrender? IIRC at that point the Germans were in retreat from the Soviets but hadn’t started their retreat through the other conquered countries yet (like Poland). What would have happened to those countries since the Soviets wouldn’t have had their armies in there to ‘liberate’ them? Would the Soviets have pressed to occupy them anyway? What about Germany itself…if it surrendered completely and unconditionally to the US directly, could the Soviets still have pressed to divide the country in two?
As to the effect on Japan, I’m not sure it would have had one. In fact, it might have made things worse as they would have been psychologically prepared for it. I think that part of what caused them to surrender in the end was simply the shock of having first one of their cities and then another obliterated…even then there were elements who wanted to fight on and only intervention by the Emp directly finally brought about the end of the war. Given time to prepare both physically and psychologically, and given just how fanatic the Japanese were, I’m thinking we would have been forced to actually invade Japan (and that the Soviets would have turned on Japan much earlier as well, meaning that instead of a partitioned Europe we might have had an iron curton situation in Asia instead).
Also, after using such a bomb on the Germans there MIGHT have been some protest about using another one on Japan…racial hatred aside. Or the president might not have been willing to use it after getting reports on what the ones in Germany had done.