YOU are sitting behind the Humvee where you’ve dragged a wounded soldier. You’ve wrapped the gaping hole in his leg, given him a shot of morphine and radioed up the line for help. Your eye is trained on a distant, hazy point through the scope of an assault rifle. You can see the tiny, magnified bodies of your enemy. Maybe they are waiting for another explosion. A bigger one. Your heart starts pounding harder. The temperature is over 100 degrees. The kid next to you, a kid you always found slightly annoying, with his Massachusetts accent and his unwillingness to walk in the front position of the line, is now holding a bloody pad to his thigh and biting down on a bandanna to keep from screaming. Sweat is pouring down his face.

There is no easy way out. You simply have to wait and try not to give away your position. Through your scope you can see their rocket launchers in a pile on the ground.

What you do, without moving your hands from the rifle, is to start breathing, because you realize you have been holding your breath for a long time. So you deepen it. Slow, deeper, deeper. The hiccups of fear start to mellow out. You can feel your belly soften a bit. Then you visualize your breath. In the left nostril, out the right. In the right, out the left. After just a minute, the mad thumping in your chest begins to slow. You hold the fingertips of one hand to your forehead to calm the fight-or-flight response so you can think clearly. The situation has not changed, but you feel yourself change, and you are now able to deal with it.

Back in the safe and cold green mountains of central Vermont, I walk into the yoga room to face a roomful of boys and girls. They are 17, 18, 20 years old, but they seem more like boys and girls than men and women. The stress in my students’ lives is not at combat level. Yet. Right now, most of them have the stress of being in the Corps of Cadets at a military college. That means P.T. at 5:30 in the morning, and constant building, running, gunning, learning, hiking, jumping and being yelled at.