Armed Liberal has a good post on the fantasy world of perfectionist war critics:

...in the reality-based America where I live, we do bad things all the time. The good news is that we tend to do a far better job of self-correcting (note that the Abu Ghraib folks were already or about to be indicted when the story broke - the military justice folks had received the info, acted, and were busting the perps - one of whose lawyers released the imagery as a negotiating tactic) than, for example, the Greenpeace-killing French DSGE do...

...All actions and systems involve mistakes, are imperfect, have undesirable unforeseen consequences. We're human, and fallible. We have imperfect information, we often act out of fear or prejudice or laziness or greed. This has been a part of the human condition as long as there has been a human condition to have. It is the root of tragedy, the most human of art forms...

In an imaginary world in which we were omnipotent, yes, none of this would happen. We could identify our opponents with perfect accuracy, and disarm and restrain them without harming anyone. Once restrained, our procedures would be firm, gentle, and correct in every degree.

It's funny, but I pretty much think that's what we're doing now, with a massively narrow span of error.

Amen to all that. Just to choose one example from recent history, the D-Day landing hung by a hair. If Hitler had committed his Panzers right away, it would have been a bloody defeat for the Allies. But he didn't and it wasn't: a reminder that the enemy also makes errors.