Darrel described a Baghdad street battle that scarred him -- and scared him about himself. He was in an armored vehicle. Other soldiers were riding on the outside, when it came under attack from an enemy armed with rocket-propelled grenades. One of the soldiers riding outside was hit and injured severely. Darrell told me the scene still returns to him in the nightmares he suffers every night. "I look at him and he is bleeding everywhere. He's spitting up blood." Someone had to take his place on the outside, Darrell realized. "Me, I'm gung-ho. I go up there. There're explosions. They tell us if you're under attack, you open fire on anybody in the streets. They say they're no longer innocent if they're there. I take my weapon and I find someone running. I point and I pull my trigger, but my weapon is still on safe."

By the time Darrell clicked it over to fire, he realized he was about to shoot a kid who was running away from the violence, a kid he was by then sure was not part of the battle. But what was most traumatic for him were his own emotions. "I'm angry. My buddy is dying. I just want to kill." He told me he realized then he had become a different man, changed by the pathology of war and the suffering of the innocents. "When I first got there, I was disgusted with my fellow soldiers. But now I'm just the same. I will kill innocent people, because I'm not the person I was when I got there." The attack ebbed, and Darrell survived it, as did the running boy.