The Taliban fighter crouched in a muddy field about 100 yards from Highway 1. The mid-afternoon sun melted the last patches of winter’s snow as he waited for an American convoy to pass.

Three miles away, Lt. Col. Robert Horney and his soldiers pulled on body armor and climbed into their vehicles. The trucks were rolling when one of Horney’s junior commanders suggested that he delay the convoy until dark, when insurgents rarely attack vehicles with improvised explosive devices, or IEDs.

“We are the U.S. Army,” Horney thought to himself with some irritation. “We go where we want to go.”

The vehicles rumbled down a rutted dirt road, through a small village and toward a highway culvert where the Taliban had set about 40 pounds of explosives in a yellow plastic jug.

The Taliban fighter pressed a button, and a charge of electricity raced through copper wire. The highway exploded, shooting chunks of rock and dirt hundreds of feet in the air, nearly missing one of the American trucks. It shook and then lurched hard to the left.

“IED, IED, IED,” Horney’s soldiers yelled.

They called the name of the gunner, exposed in the turret. He did not respond, so they yanked on his pants. The gunner’s ears were still ringing from the blast when he ducked into the vehicle to say that he was all right.

The bomb tore a five-foot-deep hole in an already pockmarked highway that the U.S. government paid $230 million to pave and that Horney’s troops were supposed to protect. It showed that even as the U.S. military has pushed Taliban fighters from many strongholds, the enemy retains significant havens in this region only 40 miles from Kabul, the capital. And the near miss shook Horney’s confidence.

Horney, 41, broad-shouldered with brown hair shaved close to the scalp, climbed down from his truck. He suppressed a surge of anger. He was the commander of an 800-soldier battalion and needed to project an air of steadiness and calm. His troops fanned out in a defensive posture.

Horney noticed the hastily buried wire glinting in the sun and followed it until he reached the spot where the insurgent had been waiting. He approached a nearby farmer, gray-bearded and bent from a life in the fields.

Why didn’t he report the bomber to Afghan soldiers a short walk away? Horney asked.

The Taliban were everywhere, including the Afghan army, the farmer replied. “There is no one I can trust,” he insisted.

The two spoke for a few minutes about the man’s crops and his nine children. As Horney shook his hand and turned to leave, the farmer had a question. “Was anyone hurt?”

A vital highway

Horney grew up in Lebanon, Pa., where his father was a recruiter for the Army Reserve. He’s fit, with an open, friendly manner and a slight drawl — an accent best described as career Army. His twin brother is also a soldier.

The prospect of ceding any territory to the Taliban as U.S. troop numbers fall over the next year is painful to him. President Obama has mandated that the 30,000 additional troops that he ordered to Afghanistan in late 2009 return home by the end of September.

“We are being forced to prioritize by the reduction in troop levels,” he said. “My problem is that I am finding more places I want to go and not less.”

For most of the war the United States maintained a relatively light presence on Highway 1. Then, on a single day in August 2008, insurgents burned 60 trucks that were hauling supplies on the highway for NATO. They cut the road with massive IED explosions.

Highway 1 does not look especially important. It is just a narrow, two-lane ribbon of blacktop.

But in a country with a weak, corruption-plagued government, the road linking the capital to Kandahar, the country’s second most important city, was seen as essential to holding Afghanistan together. The chaos on a vital route so close to Kabul was contributing to a siege mentality in the capital. More than 3,000 U.S. troops were dispatched in 2009 to clean up the mess.

Today Horney has about half of his force protecting Highway 1. The other half holds down two outposts on a dirt road 15 miles to the west of the highway. Insurgents could use the rugged trail, known as “Shadow Highway 1,” to smuggle weapons into Kabul.

On a visit to one of the bullet-pocked outposts on Shadow 1, Col. Mark Landes, Horney’s commander, asked how many insurgents were in operating in the area around the shared Afghan-American base.

“A lot,” Horney said.

“I am so tired of words like ‘a lot,’ ” Landes prodded. “I don’t know what they mean.”

Within a year most of the American troops in Horney’s sector will be gone and the Afghans will be in control. What would happen if the United States left the outpost on the shadow highway? Landes asked.

“If we pull out, the Afghan army and the Taliban will find a way to live together,” Horney guessed.

‘My pride is hurt’

Three days after the near-miss bomb attack, insurgents crept up to Highway 1 and fired a volley of rocket-propelled grenades into two tankers hauling fuel for NATO.

The attack occurred directly in front of one of Horney’s outposts. American snipers, perched on the back wall of the base, shot at the attackers as they fled through a nearby village. Capt. Adrian J. Koss, the commander, and a team of U.S. soldiers pursued them.

By the time the Americans reached the village the locals had disappeared into their walled compounds. The insurgents were gone. Koss and his men returned to their base, passing by the village bazaar stocked with Pop-Tarts, PowerBars and energy drinks stolen from the supply convoys in past attacks.

The insurgents who launched the attack on the fuel tankers were not interested in looting. They wanted to send a message that the Americans could not even safeguard the stretch of highway directly in front of their outpost.

“My pride is hurt,” Koss admitted. “It is my task to secure that highway.”

The trucks burned outside the base for 36 hours — the black oily clouds visible for miles. Horney called Koss at his headquarters and told him to drag the trucks off the highway and out of sight as soon as possible.

“The enemy here feels very confident,” Horney said later, reflecting on the rocket-propelled grenade attack and the near-miss IED strike on his convoy. “There’s no fear of getting caught or killed. We’ve got to put more fear in the insurgents and get more confidence in the population.”

The Afghan commander

Horney’s best hope for securing Highway 1 is Lt. Col. Mohammed Allam, who commands the Afghan soldiers in southern Wardak province.

For months Horney has wanted Allam’s troops to accompany his men into the villages that border the road and offer the insurgents a haven from which they can attack. Allam’s soldiers preferred the relative safety of the highway, and Horney could not order the Afghan soldiers to accompany his men.

He needed Allam to write a patrol schedule.

“I have no idea why it is so hard,” said one of Horney’s company commanders.

In late March after months of encouragement from the Americans, Allam started to make plans for joint U.S.-Afghan patrols into the villages.

Horney invited Allam and his staff officers to the U.S. chow hall for a dinner celebrating the Afghan New Year. Allam, who is in his mid-50s, is tall with a ruddy face and stooped shoulders. As a young officer fighting alongside the Soviets, he took a bullet to the chest. The enemy round left a spidery scar a few inches from his heart.

The dinner was Horney’s way of showing his support. Allam and his staff officers — skinny, middle-aged men with gray-flecked beards — sat on one side of the table. Horney’s officers — clean-shaven and in their early 20s — filled out the other side. There was little conversation.

Horney dug through his supplies and found an unopened can of eggnog, which Allam had enjoyed at an earlier dinner.

“This is the last eggnog in all of Wardak province,” Horney announced.

They each delivered toasts praising their battalions’ partnership and lamenting the hardships that came with being away from home.

Two days later Allam produced the patrol schedule for the villages around the highway.

“This mission is important to us,” Allam told his officers. “We are trying to awaken our personnel from sleeping on the highway.”

Horney’s officers were skeptical that the Afghans would execute the village patrols without the Americans pulling them along. “If they don’t want to do anything, what do we do?” one of his company commanders asked.

It was up to Allam to inspire his men, Horney said. “Success isn’t you making them do it,” he told his officers. “You guys have to realize it is going to be Afghan-led here very soon.”

Suspicious activity

A week after the attack on Horney’s convoy, one of his soldiers spotted three Afghans on a grainy video surveillance feed digging at night in the exact spot where the earlier bomb had been set.

Capt. Ryan Harmon, one of Horney’s company commanders, dispatched a platoon of U.S. troops and a platoon of Afghans to the culvert. Two F-16 fighter jets, flying out of earshot at 18,000 feet, moved into position. Horney hovered behind his company commander.

The two officers stared at the shadowy figures on the video screen. Before they could clear the F-16s to shoot they had to be positive the men were putting in an IED. Some civilian trucks sped past the culvert.

“Look at them,” Horney said. “When the trucks rolled by, they laid down.”

“They are doing some suspicious [stuff],” Harmon agreed.

The video surveillance feed, which did not clearly show the men carrying weapons, was not definitive enough to call in an airstrike. The American ground troops were a 10-minute drive from the culvert. A platoon of Afghan soldiers manning an observation post on the road was closing in from the other direction. Because several of their vehicles weren’t working, they were walking. They were about 15 minutes away.

Harmon cursed. He worried the men would escape.

“What’s the plan?” Horney asked. “Are you going to roll up and drop ramp?”

“Yeah, just kick them in the face,” Harmon replied.

Horney’s commanders have been pressing the Afghans since August to shift more troops to this stretch of highway, from the relatively peaceful area to the north. So far it has not happened.

A successful strike was just the sort of operation that would put some much-needed fear into the insurgents and give the Afghans a boost of confidence as the U.S. mission in Afghanistan began its inevitable wind down.

Horney dashed out to take an unrelated call from one of his other company commanders who had received a tip that some insurgent leaders were hiding in a nearby mosque. The officer needed help persuading the Afghans to search the building. In the end the Afghans found nothing.

After about 15 minutes, Horney returned. Harmon had dropped to one knee and was hitting his forehead with his radio handset. The three figures had ducked into a dry riverbed and disappeared into a nearby village as the U.S. and Afghan troops approached. There were some fresh shovel marks in the culvert, but no IED material left behind.

“How is it going?” asked Horney.

“Escaped,” the younger officer replied.