Seems to me that the two guys who wrote the letter have a better idea than anyone on this forum whether what they did was right or not...They were there right? Or am I misunderstanding the letter?

If I shoot someone just for the hell of it (not saying that's what happened!) it would be kinda strange for someone who wasn't there to tell me I really did it because I was threatened.

War is an ugly, nasty thing. I can't pretend that American soldiers don't do ugly, nasty things just because they are Americans...