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.

Each Javelin round costs $80,000, and the idea that it's fired by a guy who doesn't make that in a year at a guy who doesn't make that in a lifetime is somehow so outrageous it almost makes the war seem winnable.

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.

One interesting thing I found was that if you take an affluent modern society and collapse it during a crisis, like a war or a natural disaster, people begin relating in a more ancient, organic way. They're functioning in small interdependent groups and putting others first. And another irony is that even in terrible times, cooperating makes people feel good.

Ironically, though our society of affluence brings safety and stability, it doesn't bring psychological health. As wealth goes up, suicide and depression rates tend to go up. I read one study that compared women in North America with women in Nigeria, and the group with the highest rates of depression was urban North American women, which is the wealthiest. Now, there are obviously huge stresses that come with poverty, but the poorer the society, the more collaborative people have to be.

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.

If you get an infection, you get a fever; the fever is your body dealing with the infection. If you get traumatized, your mind and your brain have a reaction to that trauma. If you're not dreaming about it, something's probably wrong.