Let me add a further clarification here, then. Even in the case when you are intending to hit the sniper, you must actually aim at the sniper. You cannot simply fire a machine gun in the sniper’s general direction and claim to be trying to hit the sniper and avoiding the child. Hitting the child in this case would still cary moral culpability (criminal negligence, perhaps?).
On the other hand, if you had a sniper aiming at the sniper, took careful aim and shot, and at the last second the child jerked his head and got in the way of the bullet, then you are probably not culpable. You were making a good faith effort to respect the line between combatant and non-combatant.
I’ve got a few earlier posts on this. If you have a specific rebuttal please point it out, but I don’t want to simply restate myself in this posting.
In classical just war theory, what you are saying is similar to discussions on the morality of a siege. I’m not sure the same applies when an entire city is slated to be blotted off the face of the earth. Essentially, what it comes down to is that I refuse to accept an *entire *city as being a legitimate target, which is what an atomic bomb essentially does. I think the distinction between legitimate and illegitimate targets must be scrupulously maintained.
Also heard that there were no warnings and that, in Nagasaki, the leaflets actually came *after *the bomb was dropped.