It amazes me that some people can sit back thousands of miles away, sitting in the comfort of their easy chairs and criticize the actions of a soldier that that has to make decisions in a combat situation, from in some case a mile away.
The opening scene of the American Sniper gives just a small hint at the complexity of thier job. Is the person in their scope intent on harming American Troops or are they innocent people just trying to survive a war they want no part of? Put yourself in the situation, you are the one making that decision. Are you going to error on the side of protecting your fellow soldiers or are you willing to take the chance and sacrifice those soldiers to protect against being charged with a war crime. IMO that is a situation that not one of us in qualified to judge.