Great, let's cut to the chase. Leaving aside all points of contention such as overtures to surrender earlier in the war, the idea that an invasion was an unavoidable choice, the silly notion of children and old women charging US Marines with pointy sticks and get to the real question: If we remove "we had to!" from the equation, do you consider the deliberate incineration of hundreds of thousands of civilians (yes, even civilians in a country with whom we were at war) to be a moral decision that reflects your idea of what America is and should be about? If you ask many people about the decision to drop the atomic bombs, they attempt to brush it off without any real thought. Why? Because moral questions can be very uncomfortable. That is precisely why they need to be asked.
By the way, that is exactly how most abortion supporters respond to moral questions, if that helps give you any perspective.