I disagree with your reasoning for it being morally correct, because they were warned. Yes, it probably saved many other lives, by dropping the bomb, than it actually killed, but tell that to the family members of those who innocently died. Using your reasoning, I guess Al Quida could also say that we were warned, but, IMO, that wouldn't make it right.
As for soldier and civilian being nearly indidstinguishable, if our enemy was invading our country, I think there would be many civilians taking up arms and wearing camo, and driving HUMMERS, making them nearly indistinguishable from the military. ;-)
I worded that poorly. I don?t believe that warning the Japanese made it morally correct, but I believe it mitigates what is morally lacking rather than justifies it. The primary moral reason mitigating the act was the fact that the targets did have military significance and secondary because Japan was engaged in total war. As scooterbug said, the fact that it is still debated to this day shows that as a culture we understand the significance and impact of the decision. Also, the fact that we look at it as wrong as a default position until proven acceptable emphasizes the difference between that and something like bombing civilian markets.
Also, I?m not arguing that dropping the bombs was morally acceptable because it saved lives, but I?m listing that as something to list in the pro category after the decision has been made based on something that fits within the core beliefs of what allows us to at least get some sleep at night.