Just a note that on this thread, this point remains undisputed:
It's primarily unjustified because it set the precedent that it is OK to use weapons of mass destruction under any circumstances. I disagree. The use of WMD's is *never* justified. It's an evil act regardless of how you dress it up. Worse, from a practical standpoint, the precedent puts at risk many innocent people around the world. Sooner or later the bad guys are going to get the bomb, and they are going to point to Hiroshima and Nagasaki to justify their use of it. They are going to argue that bombing New York, or Toronto, or Los Angeles is the only practical way to win their conflict, and it's going to be a hard argument to refute unless you insist that Hiroshima and Nasgasaki were equally evil.