Begin soapbox. While I appreciate, and more or less agree with, the other ideas expressed here, I need to play devil's advocate.
I served in the U.S. Navy for four years (1994-1998). Without going into much detail, personal and economic realities compelled me to take that career detour, and in retrospect it was not such a bad deal.
Granted, the US military is not for everyone. Granted, it is less than admirable in a number of respects. Granted, you could get killed or maimed quite easily, even in peacetime. In fact even conceding all the points made on this page by other noders, military service, for some people, still is not that bad a choice.
In my brief tour of duty, I met lots of people who came from circumstances of extreme poverty, gang activity, drug abuse, crime, and a host of other problems. Some, like me, were merely suburban kids that needed some discipline. Regardless of what brought them there, the military brought them a degree of physical security, steady income, a support structure, the possibility of college, and invaluable life skills (self-discipline, integrity, honor, etc). For many people, and I was told this dozens of times, the military was the only way out of whatever mess they were in, their only hope of having a decent life.
My point is this: military service is not for everyone but there is a significant number of people in this country who would be in jail, on welfare, gang-banging, or who-knows-what without it. End soapbox.