I knew people that came home from Iraq and had problems adjusting. If you can witness battle and not be scarred, you're not right to begin with. HOWEVER, none of them took their issues out on 19 year old strangers.
I disagree. It is a matter of perspective. If you aren't prepared and there with a specific mission then you shouldn't be there. After that, forget empathy and sympathy. To paraphrase Patton, leave that to the other guys.
What about surgeons, EMT's, cops, etc., that witness that stuff all the time. Would you say they are not right?