Making enemies.

• Author: Rosen, Nir

I'm in Al Qaim, in the Anbar province of western Iraq, by the Syrian border. The men of the 1st Squadron, 3rd Armored Cavalry Regiment, occupy what they have named the Wild West. Lieutenant Colonel Gregg Reilly is the SCO, or squadron commander, of Tiger Base. A relaxed Californian, he is comfortable answering tough questions but gets tense for the first time when asked why the United States is in Iraq. He removes his legs from the desk and places an elbow on the table as he leans his forehead in his palm. "We're here for the right reasons, to enable this region of the world to progress," he says. "And America has always had to be there to stand up for me basic human rights of people. The reputation of the United States is on the line."

Most of Reilly's troops echo his sentiments, but not all the men are thrilled to be in Iraq. When asked how long he had been there, one enlisted twenty-one-year-old snaps, "Way too long. When we first got here it felt like we were doing something good. Now it feels like a waste."

"If we find weapons of mass destruction it was worth it," says another twenty-one-year-old. "But if we don't and we're just here because Bush wanted to finish what his daddy started, then a lot of boys died for nothing, and that's fucked up."

Staff Sergeant Joseph Alfeiri expresses sympathy for the Iraqis. "I wonder how I would feel if someone was breaking down my door," he says. "Or if it was my grandfather who didn't understand instructions at a checkpoint and panicked and was shot by the foreign force."

Sergeant Scott Blow, a twenty-seven-year-old from Denver, worries about security. "Nobody knows who the enemy is here until they shoot at you," he says. "Any time you kick down a door, you don't know what to expect."

On June 7, one of Reilly's soldiers, Sergeant Michael Dooley, was standing at a checkpoint when a car approached containing three men. Two of them called out that their friend was injured and needed attention. When Dooley approached the vehicle to assist, the men shot him in the face, killing him immediately.

In early October, Reilly decides he has enough "actionable intelligence" to pursue those who are attacking his soldiers every day. "We have the most concrete set of targetable data in Iraq," Reilly says of the operation code-named Tiger Strike. "We have built this over many months with multiple sources." He has two organizational charts on his wall. One chart is for Al Qaeda cells, including safe houses, financiers, and fighters. The...