The platoon sergeant poses a simple question to the men of 3rd Platoon: “What do you consider success on a mission?”

There is an uneasy silence in the dark chow tent. In a few months, the U.S. Army will bulldoze its portion of the base, part of America’s slow withdrawal of combat forces from Afghanistan. All that will remain here in this isolated place is a small Afghan army camp and a mostly empty government building with a mortar hole in its roof, the sum total of 11 years of U.S. counterinsurgency efforts in this district 65 miles south of Kabul.

Sgt. Gary M. Waugh, a soldier on his second Afghan tour, takes a stab at answering the question. “Us not doing a thing,” he says. “Not firing our weapon.”

A few of the soldiers rest their chins on the butts of their rifles. A diesel generator drones in the background as the platoon sergeant surveys his men.

“Right answer,” he replies.

America’s war in Afghanistan has consumed close to $500 billion and cost more than 2,000 American lives. By December 2014, the last American combat troops are scheduled to leave the country. American-led combat operations are expected to finish by the middle of next year. But the war is already ending at little outposts throughout Afghanistan as the U.S. military thins its ranks and tears down bases.

How does a war end? In Jaghatu, these soldiers are learning one way. It ends with resignation, isolation, boredom and the soldiers of 3rd Platoon striding out of the chow tent and into the bright light of a warm September day. Now that they had defined mission success, they had another question: What exactly was the mission anymore?

Isolated soldiers

The U.S. troops at Jaghatu are about as isolated as soldiers can be in Afghanistan. Surrounded by mountains and enemy-controlled terrain, the Americans receive almost all of their supplies by helicopter and weekly parachute drops.

Six months ago, before the current soldiers came, the troops’ mission was clearer: to rout the Taliban from the area. In May, a platoon of Americans in Jaghatu fought a four-hour battle with the Taliban for “Antennae Hill,” a large outcropping of rock, scrub and dirt with a commanding view of the valley to the south of the outpost.

When 3rd Platoon, part of 2nd Battalion of the 173rd Airborne Brigade, arrived this summer, its members watched the shaky helmet-cam footage that their predecessors had taken as they cursed, sprinted and fought their way to the top of the hill without serious casualties. Pfc. Dillon Guillory, 24, played and replayed the video on his laptop, anxiously waiting for his moment.

Except for occasional patrols, Guillory has spent most of his deployment manning a guard post that overlooks a tattered Afghan flag and the crumbling government building. In Jaghatu, U.S. troops don’t charge up hills after the enemy anymore. They don’t search houses, and they rarely meet with Afghan village elders. Those jobs are supposed to be done by the Afghans.

The Americans’ main mission is supposed to be training the Afghan soldiers with whom they share the base, but Guillory is one of only a handful of 3rd Platoon soldiers who interact with Afghans.

(gene thorp/The Washington Post)

“How are you doing?” Guillory asks as he checks the badge of an Afghan worker who speaks no English. “Done with work already?”

To pass the time, Guillory and the other soldiers lift weights and box on a small square of dirt to the screams of Rage Against the Machine’s “Street Fighting Man.” They eat Baskin-Robbins ice cream that floats to earth in weekly parachute drops.

Guillory speaks via Skype to his wife in Lafayette, La., as often as twice a day, more frequently than he talks to any Afghan and many of the soldiers in his platoon.

He watches on his laptop computer and coaches her as she removes the stitches from their recently neutered pit bull, Nelly. “You’re doing great,” he soothes as her hands shake. “You are not going to hurt him.”

She sends him video real-estate listings of houses that she dreams of buying when his enlistment ends. The latest is a four-bedroom home with triple-crown molding, a glass-enclosed fireplace and a $313,000 list price. “I’ve watched it three times, and I can see us living there,” he messages his wife.

In his three months in Afghanistan, Guillory has experienced only one moment when the war seemed real, immediate and dangerous. In late July, the platoon was sitting on a ridgeline watching some Afghan troops when a burst of enemy machine-gun fire exploded around them. Guillory threw himself on the ground, crushing his compass with his body armor, and slid to cover on his stomach.

“The whole thing only lasted 15 or 20 seconds,” he recalls.

One of the enemy rounds ricocheted off a rock and struck Pfc. Adam Ross, 19, in the back of the head just below his helmet. The medic worked to stanch the bleeding and called out the details of the injury to Guillory, who scribbled the information on his hand and then radioed the outpost.

The soldiers did not learn that Ross was dead until they were back in their tent. There was no cursing or screaming. Just silence. Guillory, who had not known Ross well, snapped a picture of the writing on his left hand. He had been so shaken that instead of writing “Back of Head,” he had scrawled “Head Back.”

The next day, the medic carved Ross’s last name and the date of his death into a piece of splintering wood in Guillory’s guard shack. Guillory added the 173rd Airborne’s winged insignia in white marker and wondered how he had not been struck, as well.

Weeks passed and the memory gradually faded, until it became just another memorial scratched into a piece of wood and surrounded by graffiti from previous units’ tours.

Now the video real-estate listing from his wife seems as real as anything in his life. It is sundown, and Taliban gunfire pops in the distance. Afghan troops respond with a machine-gun blast. “Why would you need a fireplace in Louisiana?” Guillory wonders aloud.

Their next patrol

Sometimes, the soldiers at Jaghatu have days when they don’t feel like soldiers at all. Second Lt. Andrew Beck, the leader of 3rd Platoon, calls his men together to brief them on their next patrol, which involves sitting on a ridgeline while Afghan police search a small village.

They meet in front of Beck’s hooch, a windowless metal container ringed by six-foot-tall barriers built to shield against incoming rockets and mortar shells. Beck, 25, urges his men three times to be cautious. “The general in charge of Afghanistan’s intent is not to destroy the Taliban,” he says, unintentionally overstating the top commander’s guidance. “I know that sucks. His intent is to minimize civilian casualties.”

Beck’s platoon sergeant speaks next: “You guys have been here more than two months. Just keep doing what you are doing.”

What exactly are they doing? Even their commanders are not sure. The Jaghatu outpost was built in 2010 to interdict Taliban fighters who were believed to be moving weapons through the area and into Kabul. But there were never enough U.S. or Afghan troops to pacify the district or find the enemy weapons caches. Even the addition of about 450 Afghan soldiers this spring has not improved security.

Today, U.S. troop levels are falling, and American commanders are realizing that there are severe limits to what they can accomplish in the time they have left in Afghanistan. Beck feels those constraints most acutely when he passes through the Jaghatu bazaar and stares through bulletproof glass at the rickety stalls and bearded shopkeepers.

“Every time I drive through the bazaar, I wonder what is going on 100 meters outside the base,” he says. The Americans pull some intelligence from the district police chief, but never enough. “You feel useless,” Beck adds.

It is a little after 11 a.m. when Beck and his platoon return from three uneventful hours of watching the Afghan police search the village to the west of their base. He gathers his 28 paratroopers in the outpost’s conference room to discuss what they have seen on the patrol.

“Because we have limited missions, we have to make every one of them count,” he says.

Beck graduated near the top of his West Point class in 2011 and had his pick of units; he chose the 173rd Airborne because he knew it was headed to Afghanistan. He expected that he would be leading his soldiers on helicopter-borne assaults and hoped he would be responsible for the security of a few Afghan villages.

The lieutenant asks his men if they noticed anything unusual when they were sitting on the ridgeline watching the village. Silence. “Okay, the pattern of life looked normal, surprisingly normal for what we thought could be an insurgent haven,” he says.

Soldiers stare blankly or doodle in field notebooks. Chairs squeak. The soldiers steer the conversation to a larger issue: They do not understand why they are doing so little.

For weeks they’ve been told that their primary mission is to help the Afghan army and police units in Jaghatu improve. A young private complains that they barely ever see or speak to the Afghan troops. A more senior sergeant echoes him.

There is a new Afghan battalion commander at the base, and Beck suggests that he may be more open to allowing his men to train with the Americans, though it is too soon to tell. “If the Afghans don’t want to take advantage of working with the best Army in the world and the best platoon in this brigade, it is their fault,” he says.

A loyal ally

On a Friday in which no patrols are scheduled, Beck pays a visit to America’s longest-serving and most loyal ally in Jaghatu — the district’s 24-year-old police chief. He walks through Guillory’s gate and into an adjoining, walled compound that houses the government center building with the hole in the roof.

Beck and a few of his soldiers have come to take pictures of the police chief’s men decked out in new body armor, helmets and goggles that the Americans had given them earlier that morning. The Afghan police stand stiffly between a flower bed and a wall scorched from insurgent rocket-propelled grenade blasts. A U.S. soldier adjusts a helmet that is slightly askew.

“A picture with your gun?” the police chief asks one of Beck’s men.

So far this year, Afghan soldiers or police officers have been accused of killing more than 50 U.S. and allied troops. There’s an awkward pause as the soldier glances at Beck for guidance and then strikes a last-second compromise, popping the magazine out of his gun, checking the chamber for a stray round and handing it to the police chief.

The chief doesn’t seem to register the soldier’s move as a slight, but it bothers Beck. “He is the guy we trust most, and we have to take the magazine out of the rifle,” Beck says.

Beck hands the young police chief his loaded M-4. “One more picture by the truck,” he says.

“When you guys leave, you are going to take everything?” the chief asks. “All of the helos and the armor?”

“I don’t know,” Beck replies. “You’ll probably know before me.”

“I think your Army is tired,” the chief says.

Before Beck returns to his base, the police chief has one more request. There’s a pile of cardboard left from one of the American airdrops that morning, and the chief asks if he can have it. They are out of propane gas and need something they can burn to cook their dinner.

Expecting a firefight

Finally, after weeks of waiting, Beck’s soldiers get word that at last there is going to be a mission. It will be their biggest since arriving in Afghanistan. More than 100 Afghan soldiers, 15 Afghan police and about 40 Americans will return to the area where Ross was killed. Everyone is expecting a firefight.

The night before they leave, Guillory talks to his wife on Skype. “Hey, babe, I got to wake up early for work tomorrow,” he tells her at 8:15 p.m. He flips off the light in his bunk, but his wife keeps talking. He tries again 14 minutes later: “Okay, I need to go to bed, babe. I’ll call you tomorrow.”

After two more tries, she says goodnight around 8:40 p.m.

By 3 a.m. the tent is bustling. Boots thump on the plywood floor, and soldiers stuff bottles of water and prepackaged meals into their assault packs.

By 3:30 a.m. they are gathered in front of their trucks. The platoon sergeant double-checks the soldiers’ body armor, thumping the ceramic plates with his fist and tugging on loose straps. The medic reminds the men that they need to act quickly to stabilize wounded colleagues. “Stop the bleeding and then go to the airway,” he says. “If you lose the airway, you lose the patient.”

Beck speaks last, and this time he does not preach caution. “It is going to be a good day,” he says. “The enemy . . . has never seen this much Afghan army or coalition forces coming at them. We are going to knock them on their a--.”

The platoon’s trucks roll through the outpost gate, pausing on the edge of the desert. One by one, they test fire their heavy machine guns as the sun peeks over the mountains of the Jaghatu bowl. The .50-caliber gun on Guillory’s truck is one of the last to shoot, the loud ca-chunk thundering through the valley.

“The terrorists are up now,” Guillory yells.

“All right, let’s fire these weapons at the f---ing Taliban,” the gunner says.

The armored trucks lumber down the deeply rutted dirt road past a handful of wary-looking Afghan families. At first the soldiers joke with one another to stay loose, but as the truck edges closer to the insurgent-controlled ­villages the chatter ebbs.

Over the radio, there is an order to halt the convoy. The armored vehicles edge to the side of the road and wait for more instructions. A few minutes later, they receive a second order: Return to base.

Hundreds of miles away in Helmand province, Taliban fighters dressed in Army uniforms have penetrated the heavily defended Camp Bastion, where they killed two Marines and incinerated six U.S. fighter jets, each worth about $25 million. Senior military officials in Kabul are advising their field commanders to scale back missions with Afghan forces for a few days.

The platoon sergeant and Guillory climb down from their armored vehicles and walk back to the outpost. The soldiers who had steeled themselves to fight are once again preparing to sit.

“We look really bad to the Afghans right now,” the platoon sergeant says to Guillory. “We are supposed to be supporting them, and we left them.”

“I don’t understand why we aren’t just going out anyway,” Guillory replies.

Instead, Guillory returns to his war: a view of the mortar hole in the government building and a guard post with little to do. He chews through a pack of gum. There are six months left in his tour and 26 months left before U.S. combat troops leave Afghanistan. “I am sure there are people that have a bigger understanding of the war than us little guys,” he says. “But at my level, it seems so stupid.”

On the other hand, they didn’t fire their guns at the enemy. They didn’t do a thing. The mission was a success.