Here's the fundamental problem. You've essentially taken a chainsaw and cut out every civilian part of their lives, and replaced it with the cold hard ability to kill another person. This has left deep, deep scars in their psyche's, and that has been aggravated by the horrors of war.
Now try to take a person who's been brainwashed, mortified, and shown dead and wounded people for
years , and make them act like a normal person again. One constraint though, it can't be bootcamp.
That's why it seems so simple in theory, but is so incredibly difficult to do. That shouldn't keep us from trying, since these men and women gave their all to defend our country, and overseas interests from being destroyed. To all the shrinks who help those soldiers out, you have the toughest job in the world, but please, keep on trying. You're the only people standing between them and insanity.

-Penguin