Sgt. Bales is a prime example: he had been sent into battle, faced death, then came home to comfort and safety. Then he was thrust back into battle, facing bombs and bullets and possible death once more, then home to comfort and safety. Again and again.
If you want to support the troops ask the right questions: What was his mental state when he allegedly killed those civilians? If he was under mental distress, why was he not removed from the battlefield?
Imagine an Afghan who came to the USA and murdered 16 people, mostly women and children, and burned their bodies. Then the Afghan government whisked the guy away and said, "Trust us, we'll take care of the matter."