No one will remember that President Obama supported the Arab Spring if it eventually fails and the region collapses back into the political Dark Ages. If we actively engage these movements with advice, with money, and, when necessary, with military force, then we get a vote in how it all turns out.

People who do really dangerous tasks can't afford to sit around and discuss the merits of what they're doing.

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.

At 19, your brain hasn't finished wiring itself. So the first time you have a good friend die, most people don't go through that at 19. Soldiers do. They're facing life in this accelerated, compressed form, and a lot of times, they're not ready for it.

A grenade launcher will easily take out a tank; a Molotov cocktail placed in its air intake will destroy one as well.

During the air war of 1944, a four-man combat crew on a B-17 bomber took a vow to never abandon one another no matter how desperate the situation. The aircraft was hit by flak during a mission and went into a terminal dive, and the pilot ordered everyone to bail out. The top turret gunner obeyed the order, but the ball turret gunner discovered that a piece of flak had jammed his turret and he could not get out. The other three men in his pact could have bailed out with the parachutes, but they stayed with him until the plan hit the ground and exploded. They all died.

Society can give its young men almost any job and they'll figure how to do it. They'll suffer for it and die for it and watch their friends die for it, but in the end, it will get done. That only means that society should be careful about what it asks for. ... Soldiers themselves are reluctant to evaluate the costs of war, but someone must. That evaluation, ongoing and unadulterated by politics, may be the one thing a country absolutely owes the soldiers who defend its borders.