Too many tours of duty, and too many days in combat!
http://www.nytimes.com/2013/05/03/health/suicide-rate-rises-sharply-in-us.html
Suicides are up (I believe) in every age group of Americans.
I've been advocating for a draft ever since the GWB years. Because our armed forces is all volunteer and consists of a small segment of your general population, there is little incentive of our political leaders to limit our military adventurism. If more or our population, specifically the upper middle and rich classes, had skin in the game, I can assure you our political leadership would think twice about sending our boys/girls into armed conflict. Those are the people who will generate the political muster to pressure our political leaders to get us out of protracted conflicts or possibly even keep us from getting to that point in the first place. Secondarily, our press needs to be more proactive and aggressive about showing the horrors of war. Right now, war looks like a video game and a thing that happens in those Arab lands. We simply have forgotten the human cost of war because it now only affects the other guy.
The military has always been a way for immigrants and poor people to work their way up the ladder in this country, but in the past even those who came from privilege were expected to serve as well.
It wouldn't solve everything, but it might quiet down the chicken hawks when they are faced with the prospect of sending their own children into the fray. These people are quick to call those poor kids "heroes" but they sure aren't sending their own kids into battle.