I. Kandahar, Afghanistan, March 5, 2012

Through the scope of his sniper rifle, Staff Sergeant Robert Bales watched a man in a spotless white tunic stroll through a grape field. The man was a few hundred yards away, dipping in and out of view as he traversed the six-foot ditches separating each row of vines. He carried a shovel and appeared to be talking on a cell phone—or was that an Icom radio? Every so often the man stopped, dug a few scoops of dirt, and moved on. He reversed direction for a few steps, then switched back again. He never stopped talking on his device.

Bales thought, What the fuck is this?

A hypervigilant infantryman in his fourth combat tour in the past nine years, Sergeant Bales had been ordered to his sentry position on the roof of his base, VSP Belambai, because U.S. forces in the area were under attack. Minutes earlier an IED had ripped through an armored vehicle as it carried five soldiers back to the base. The explosion flipped the truck, concussing several of the men inside, none seriously wounded. But Taliban strikes like these often come in clusters—a blast to get things started, followed by additional bombs targeting responders—so everyone on the base had shifted to a defensive posture. A quick-reaction force was deployed to the blast site, now a scene of smoke, shrapnel, and debris, the husk of the smoldering vehicle lying on its side. Bales had been sent to the roof to track the guy in the white tunic.

Now, as he watched, the man moved in the direction of the wreckage. This struck Bales as strange. What farmer tending his vines moved toward that kind of chaos?

The man was 400 yards from the site now and closing. He was still holding the device. Three hundred fifty yards. Three hundred. Fuck. The call Bales felt he had to make would be much easier if he could see the device the man carried. The rules of engagement allowed U.S. soldiers to take out any suspected insurgent holding an Icom radio, the Taliban's detonator of choice for remotely activating IEDs. But the guy was too far away. Bales couldn't tell. He decided not to shoot.

Minutes later, the bomb tech clearing the blast site, a Navy petty officer named John Asbury, stepped over a wall near a tall dead tree and…BOOM.

This second blast did far more damage than the first, shearing Asbury's left leg cleanly at the knee.

Two days later, Bales and a couple of dozen soldiers were sent to the scene of the attack to examine the blown-up vehicle and harvest any salvageable parts. They were out in the open, exposed to the enemy, so they worked with urgency.

At the center of the blast site was that old dead tree, about 30 feet tall, visible for hundreds of yards. It was clear that whoever'd planted the second IED had used the tree as a marker, setting off the bomb when the Americans drew near it. Bales decided it was a security threat and must be removed.

First the soldiers tried a chain saw, but the blade was too dull. So they decided to “detcord” the tree—wrap it with explosive tubing and take it down by blowing it up. That worked, but then the trunk got wedged between two adobe walls, forcing even more time and effort to free it. All this took hours, during which time Bales and his men were taking light fire from the Taliban. No one got hit, but Bales was keyed up, frustrated, worried about a full-on attack. It was late afternoon by the time they managed to drag the tree back to the base, where it sat for days, a reminder of the enemy's suffocating presence—and, in Bales's mind, of his own inability to stop the insurgent that he believed triggered the IED.

Jason Pietra; Prop Stylist: Peter Tran.

The other soldiers wanted to simply haul the tree into a burn pit. To Bales, this would not do. He wanted to destroy the thing himself. Finally, on the morning of Saturday, March 10, 2012, after fixating on this symbol of failure for three days and mostly sleepless nights, Bales went at the tree with a hand axe. It took him eight hours—in full view of the entire base—but he eventually succeeded in chopping it to bits.

“This tree was used to hurt my friends, man,” Bales told me recently, recalling the episode in an odd, detached tone. “It was used by the enemy. I had to see it go, you know?”

Later that evening, Bales would turn his rage to less symbolic targets. Shortly after midnight, under cover of a deep rural darkness, Bales slipped away from the base and walked to a nearby village, where he killed four Afghans, including a 3-year-old girl. Then, after returning to his base to reload and telling another soldier what he had done, Bales left again to murder 12 more in another village just down the road. Of the 16 people he killed, four were men, four were women, and eight were children. The youngest was 2.

A few hours later, the world awoke to what came to be known as the Kandahar massacre, the deadliest atrocity committed by an American soldier since the My Lai massacre in 1968, when Lieutenant William Calley's platoon slaughtered hundreds of Vietnamese civilians. As with that horrific chapter in our history, Bales's rampage occurred late in a long and ultimately fruitless campaign, raising uncomfortable questions about the wisdom of the war and its effect on the soldiers we ask to fight it.