Combat isn't where you might die -- though that does happen -- it's where you find out whether you get to keep on living. Don't underestimate the power of that revelation. Don't underestimate the things young men will wager in order to play that game one more time.

Of the primary emotions, fear is the one that bears most directly on survival. Children show fear. Adults try not to, maybe because it's shameful, or, in some circumstances, dangerous. The fear response is automatic, though, and your body runs through its reflexes whether you want it to or not.

How do men act on a sinking ship? Do they hold each other? Do they pass around the whisky? Do they cry?

The Army might screw you and your girlfriend might dump you and the enemy might kill you, but the shared commitment to safeguard one another’s lives is unnegotiable and only deepens with time. The willingness to die for another person is a form of love that even religions fail to inspire, and the experience of it changes a person profoundly.

I think human society for tens of thousands of years has sent young men out in small groups to do things that are necessary but very dangerous. And they've always gotten killed doing it. And they've always turned it into a matter of honor and a way of gaining acceptance back into society if they survived.

When you're scared, you're still hanging on to life. When you're ready to die, you let it go. A sort of emptying out occurs, a giving up on the world that seems oddly familiar even if you've never done it before.

No matter how many people you kill, using a machine gun in battle is not a war crime because it does not cause unnecessary suffering; it simply performs its job horrifyingly well.