Our enemies justify the wholesale killing of civilians all the time, to them it is a way to break our will to fight back, to them it is the only way to break our nerve, to them if they can make the war we are fighting too terrible we will surrender rather then fight back.
I don't believe that our Marines killed everyone in the immediate area as retaliation for a single roadside bomb and the death of one Marine, but perhaps they should have, the insurgents would have, the terrorists would have, our past enemies would have, they're fighting to win this war, and today we are fighting to look civil while losing it.
Ultimately the moral balance of history is written by the victors of any war, they get to decide who get tried for war crimes, they get to decide who lives and who dies after one side has surrendered, and we know what the insurgents, the terrorists, Al Queda, Bin Ladin, islamofascists have in mind for every American or for that matter every non Muslim in this world should we lose to them.
They won't be as civil, as kind, as gracious in victory as we have always been. they will enslave us and destroy us as a pox upon their planet, perhaps it is time to show them we can be even more brutal then they can even imagine in their wildest nightmares to break once and for all time their willingness to destroy anyone that doesn't follow their beliefs.
Nothing else is acceptable.