Going in small in Afghanistan.

With gold turbans and eyes ringed in black, the Afghan men squat in a circle in the dust, listening intently to the first US soldiers to appear in this desolate border outpost for at least a year.

"We are not like the Russians. We won't come here and bomb everything," a soldier tells them. "I have many men and many bombs, and I can bring them all," he says, as an Apache gunship swoops overhead. "But I'm not going to. I want only to use them against the bad people."

The Afghans respond initially with hard looks and few words. A tribal elder, taken aside and asked whether he knows of any Taliban or Al Qaeda fighters in the area, answers simply, "No."

"It's too dangerous," an Afghan interpreter whispers to me, "Asking that question is like announcing this man's death in the newspaper!"

The 10th Mountain Division mission into uncharted territory of Paktika Province illustrates a stark dilemma facing US forces as they push deeper into Afghanistan's lawless borderlands: How to persuade Afghans to risk their lives and divulge guerrilla whereabouts in return for a promise of security and development.

"The citizens here have had one choice: We're with the Al Qaeda, or we're dead," says Lt. Col. Mike Howard, the top US commander in Paktika. Villagers in the border districts of Gomal, Barmal, and Gayan are "completely ungoverned" and easily bribed or forced to supply guerrillas with food, shelter, and proxy fighters, he says. "Our challenge is to give them [another] choice."

To do this, US ground troops are expanding their presence in Paktika and other troubled regions of eastern and southern Afghanistan, policing more widely and aggressively. The US strategy means shifting away from large-scale sweeps and slow, top-down planning ill-suited to fighting insurgents, some officers say. Instead, smaller, more agile units - including Special Forces teams linked with Afghan militia - are branching out to win over villagers and flush out guerrillas.

"We can't hunker down in the firebases," says Colonel Howard, whose 1-87 Infantry Battalion now makes frequent, unpredictable forays far beyond its fort-like outposts at Orgun and Shkin. Last month, 1-87 joined Operation Avalanche, a series of overlapping missions along the Pakistani border that involved some 2,000 of the 13,000 US troops in Afghanistan.

Two of 1-87's missions, to Gomal and Barmal, illustrate the risks and rewards of the new approach. The first foray was to learn about the enemy; the second tried - successfully - to lure them into a fight.

At first light, the convoy of 10th Mountain Division troops winds down a steep road from the mud ruins of an ancient Afghan fort, its ghostly form overlooking the parched bed of the Gomal River as it snakes toward Pakistan.

The windswept landscape is some of the most barren the troops have seen in Afghanistan. Dry gullies and rocky hills dotted with shrubs that smell of juniper stretch as far as the eye can see.

"Keep your eyes on the high ground," Staff Sgt. Mark McCalister yells to the soldiers jostling in the open back of his cargo Humvee, as the road climbs into hilly terrain.

But the only forms appearing on the ridgelines are lifeless ones: Stones stacked by shepherds to look like wolves; or, farther on, wooden poles festooned with flags that mark Afghan warriors' graves.

Indeed, what draws US forces to this unexplored part of Paktika on Dec. 3 is an anomaly of sorts: A sparsely inhabited district with well-tended roads - roads leading to border crossings such as Khan Pass that have for centuries served as conduits for Afghan trade, and that today are known to be frequented by Al Qaeda and Taliban fighters.

Along the way, soldiers halt and search vehicles - from overladen Pakistani trucks gaudily painted and tasseled, to small white pickups filled with bearded men.

After several miles, the convoy stops at the biggest community around. It's a family village, or korani, consisting of a few mud huts, a camel tethered outside of a shop selling banana tea biscuits, and a gas station with no gas.

"Not too far from here, bad people attacked us. You all heard about that," a US soldier tells the gathered tribesmen. "They were staying there and no one told us," he says. The villagers nod.

The attack was a particularly heavy ambush five weeks earlier that killed two American contract employees of the Central Intelligence Agency (CIA) and two Afghan militiamen. It unfolded about 20 miles to the east at Khan Pass, according to US soldiers and Afghans who were both there and in Gomal.

On the morning of Oct. 25, a group of about 30 Americans and Afghans in eight Toyota Hi-Lux pickups was headed south along the border on a patrol toward Khan Pass. The day before, the group had detained a number of arms smugglers in the vicinity, and was returning to the area.

Suddenly, around 7:00 a.m., an intense barrage of fire from heavy machine guns, AK-47s, and rocket-propelled grenades (RPGs) bombarded the convoy from several positions on the high ground on either side of the road.

"My Hi-Lux and the front Hi-Lux were under attack," recounts Hamid, a stately Afghan fighter and former mujahideen from Paktika who has worked with the Americans for 1-1/2 years. "The enemy had a wedge formation. They were all prepared and experienced fighters," says Hamid (not his real name).

The fighting was close, with more than 20 suspected Al Qaeda firing down from positions as near as 30 to 40 meters away. "It was hand-by-hand fighting," Hamid says. "He could see my hand, and I could see his hand."

An RPG landed a few feet from Hamid and knocked him to the ground. He took cover and shot 14 rounds from his AK-74 assault rifle, killing, he believes, an Arab fighter. But then Hamid took three bullets himself. "I heard helicopters" and passed out, he recalls.

Meanwhile, some of the Afghan militia had bounded to the high ground, flanking and killing several enemy fighters. In all, 18 suspected Al Qaeda were killed, including Arabs, Chechens, and Pakistanis.

After a lull, the fighting reignited from a ridge and system of wadis beneath it when 1-87's Alpha Company arrived to clear the ambush site following a frenzied, 3 1/2 hour drive south from Shkin.

"These were Al Qaeda," says Staff Sgt. Jeffrey Davis of Alpha Company, noting the fighters' black tunics and diehard stance. He moved two armored Humvees to a saddle in the terrain to fire grenades into the wadis. Then, after pulling his men back to a safe distance, he used the vehicles to guide in an A-10 Thunderbolt plane that silenced the enemy with a 30mm Gatling gun.

By that time, two CIA employees, William Carlson and Christopher Glenn Mueller, had been fatally shot, along with two Afghan militiamen.

Back in the Gomal village, with Khan Pass fresh in their minds, the US soldiers scan the tribesmen's faces. "We know a lot of important people travel this road," one says. "You need to tell us when the bad men are coming."

To elicit information, the Americans offer the villagers immediate benefits: On-the-spot medical treatment, an invitation to a border clinic at Shkin, and free blankets and radios. For useful intelligence, the reward is often cash. Cooperation, by fostering security, will enable international aid groups to move in, they stress.

"We can help this area even more" than Shkin, which has gained a new clinic, a well, and businesses, the soldier says.

The villagers' reaction in this wheat- and corn-farming community is ambiguous. "Under the Taliban, things here were peaceful and good. Now, it is also good," says a tribesman named Maraha, as his neighbors squabble over the blankets. "We just want help," he says, adding that the village has no doctor and the local school was burned down.

This passive outlook bolsters the impression of US soldiers that Paktika villagers, whipsawed by decades of war, "will help whoever is in town at the moment," says platoon leader Lt. Bob Stone.

The tribal leader, Haji Sarver, blames any violence in the area on "people coming from Pakistan." He acknowledges, however, that many residents of the Gomal area "live in both Afghanistan and Pakistan."

"That's the reason these people are unbelievable," an Afghan interpreter tells me bluntly in English.

The mistrust goes both ways, however. Villagers are unsure when or if the Americans will return. A string of vehicle breakdowns, including a broken Humvee sling-loaded by helicopter down the road, underscores that US forces can police here only so often.

"If these villagers tell us something, maybe people will come the next day and kill them. Everyone is afraid," says Hamid, still limping slightly from his Khan Pass wound.

When the 1-87 convoy heads home from Gomal at the end of a four-day mission, tension rises as it enters prime ambush territory, a choke point of wooded hills south of the firebase at Orgun.

"I know this is when you need [air cover], but they have to refuel," the news crackles over the radio of Sgt. William Skerrett's mud-caked Humvee.

Without Apache attack helicopters hovering overhead, Sergeant Skerrett warns his men to keep their guns handy. His driver, Spc. Jack Horn, is more sanguine. "They're not gonna hit us with this large a force," he wages, but checks to make sure the jammer is on for remote-detonated road bombs.

It's an unenviable calculation for 10th Mountain soldiers fighting in Afghanistan, many for the second time: How to present a force small enough to invite an enemy strike, but still potent enough to defeat it.

Or, in soldier's terms: "We want to make contact, but I also want to get my 10 guys back," says Sergeant Davis, a squad leader in 1-87's Alpha Company.

The problem is rooted in a clever, virtually invisible enemy.

Indeed, ask almost any 10th Mountain infantryman on his second tour here, and he'll rattle off a list of what the enemy has learned. "They've adapted to our body armor - they know where to shoot us," says Alpha Company Sgt. Christopher Below. "These guys may be the hard-core survivors. They seem more trained than the guys in [Operation] Anaconda," he adds, referring to a major battle in March 2002 in which 1-87 fought.

Guerrillas in Paktika have a "robust" early warning system alerting them to US troop movements, according to a military intelligence officer. They communicate using radios and wireless phones.

They also easily disguise themselves. Some wear a second set of clothing under a black tunic, allowing them to drop their AK-47 and chest rack of ammunition, make a quick change, and melt into the countryside.

Others hide weapons under civilian robes, as did suspected Al Qaeda who approached three 1-87 snipers on Aug. 31. They dropped down and opened fire, killing two snipers at close range. Another fighter posing as a farmer shot from behind a tree at US troops who arrived at the scene. Once wounded, he blew himself up with a grenade, knocking two soldiers down.

Sgt. Jeffrey Grothause, an Afghanistan combat veteran whose Charlie Company squad responded that day, sums up the feeling of many troops about their enemy: "They pick and choose when to fight."

Sketching out a new mission north of Shkin in Barmal district in mid-December, Maj. Dennis Sullivan wrestles with how to best outwit this elusive opponent.

"We have a very smart, competent enemy," says Major Sullivan, 1-87's executive officer. "He will only attack when he thinks he has a chance of success." Sullivan, the son of Irish immigrants from Oxford, Mass., is the top officer at the tiny Shkin firebase, a mud-walled compound rented from a tribal leader for $5,000 a month. Sitting on a hill in full view of Pakistan's border, the base is often a target of enemy rockets.

Around the camp, soldiers clean guns and ready vehicles for the mission. The crack of a sniper rifle echoes from a makeshift range outside the wall. Meanwhile, over bitter coffee at Shkin's chow hall, Sullivan strategizes.

"If we show up too big, they take the week off and farm the field," he says, drawing a rough map of the operation.

This time, the calibrations worked, as Sullivan recounted later.

On Dec. 14, more than 100 US soldiers and Afghan militiamen set out from Shkin. At dawn the next day, they broke camp and started driving - in three separate groups - along a narrow, winding mountain pass topped with evergreens a few miles east of the border town of Mangretay.

At one juncture, steep walls of rock lined the road. The first two groups, including members of 1-87's Bravo Company and the 10th Military Police Company, passed without incident. But 90 minutes later, as the smaller third group of MPs, medics, and Afghan militia passed through, enemy rounds burst down from the high ground.

The first two vehicles of MPs sped forward while two others held back. Six more - including one that stalled - were stuck in the "kill zone," forcing their drivers and crews to take cover alongside the rocky mountain face and return fire against an estimated 15 to 20 insurgents.

Heavy machine-gun fire tore up the dirt a few yards away, while RPGs exploded in front and behind of the stalled truck, narrowly missing it. Meanwhile, the Air Force controller, Sr. Airman Peyton Knippell, guided two F-16s toward the ambush, but the jets couldn't unleash their 500-lb. bombs until the trapped soldiers could move to safety.

Freeing them was "the toughest collective challenge" of the skirmish, Sullivan says.

In an effort to suppress enemy fire, 1st Lt. Rob Eyman moved in with a platoon of armored Humvees, firing grenades and machine guns. Then a mortar section launched rounds against the guerrilla positions. After a 45-minute firefight, the soldiers escaped the "kill zone" and the F-16s dropped two bombs, causing the insurgents to flee into the forested terrain.

Two Apache helicopters flew in, spotting a camouflaged mud hut 500 yards behind the ambush site. The hut was later destroyed by an A-10 aircraft's cannon. Then, aided by the Apaches, Capt. Justin Pelkey's soldiers from Bravo Company moved to try to intercept anyone escaping. They detained a man walking away from the ambush site, who was suspiciously ignoring the Apache. He had an AK-47 and chest rack hidden under his wrap.

Along a likely enemy escape route, 1st Lt. Richard Steinbacher's platoon detained two other suspected guerrillas, including one from Pakistan's Waziristan region. Platoon soldiers also found a bunkhouse built for eight to 10 men with food and other winter supplies, military sleeping bags, and rooms with hidden entrances.

The mission, while not a "deliberately planned baited ambush," shows the calculated risks commanders must take to lure out their enemy, Sullivan says. The relatively small size and thin-skinned vehicles of the third convoy, along with the absence of aircraft immediately overhead, probably contributed to the insurgents' willingness to attack, he says.

"We presented a force of size and type that would possibly not deter the enemy from fighting, but was large enough and lethal enough to fend and fight for itself" until reinforced, he says. His soldiers returned unscathed, while two guerrillas were confirmed dead and three others wounded.

Indeed, as the ambush attempt near Mangretay showed, US forces usually overwhelm militants who stand and fight. Since arriving last summer, 1-87 has lost three men in Paktika, while killing scores of enemy. Still, soldiers here realize that if this war is fought as one of attrition, the road ahead remains long.

As the snow line drifts lower on the gray-blue peaks, 1-87 plans to step up incursions, denying insurgents a traditional winter lull in which to regroup. "If you ... hunt down the bear where he sleeps, there will be no hibernation," says Sullivan. "We will go there."

In Afghanistan's timeworn landscape, one often has the feeling that Americans troops are battling history itself. Against a backdrop of foreign occupation and warlord feuds, ethnic rifts and militant Islam, they can only hope to impose an uneasy peace.

Alone in his lookout tower back at Shkin firebase, Pvt. Gary Holt watches the sun rise over a ridge of mountains marking the Pakistani border two miles away. As the mist thins over fields below, villagers stir from their mud huts, and donkey carts take to the dirt roads. The smoke of cooking fires hangs in the air.

"It seems this place hasn't changed much since Kipling," says Private Holt, mature beyond his 20-odd years. "This place is like the last frontier."

In Paktika, the US presence has allowed a degree of progress to unfold. Hundreds of new mud-brick compounds housing extended families have sprung up around Shkin and Orgun, while stores, and some industry have moved in. Schools have opened. Meanwhile, US troops are making inroads to improve security in hostile areas such as Barmal.

Still, a degree of success at Shkin, like a pebble in a stream, has shifted the flow of insurgents to other border crossings.

"We're succeeding in disrupting their operations and denying them sanctuary within our area," says Sullivan. "What I can't say is whether we are having a long-term impact. I don't know how easily they regenerate combat power."

In the end, Sullivan and other officers agree that US forces are only an "interim fix" until the Afghan government and a national army gain strength.

"What's interim? A year or 40 years?" he says. "Ask me in 40 years."

For U.S. troops, Paktika's challenge lies in its network of border crossings, from major mountain passes to shepherd trails. For centuries, the region's fiercely independent tribes have freely visited kin across the border - a poorly marked, British colonial vestige known as the Durand Line. Drawn in 1893, it has been ignored by the ethnic Pashtun populations on both sides.

Yet today the porous border also serves arms traffickers and drug smugglers as well as Al Qaeda terrorists and Taliban insurgents concentrated in the neighboring Waziristan regions of Pakistan. There, the Taliban, who are also mainly Pashtun, find safety in the customary hospitality of Pashtun tribes. They operate training camps and draw recruits from fundamentalist Islamic schools known as madrassahs. Meanwhile, they regularly infiltrate Afghanistan to stage attacks on military and civilian targets.

Stepped-up Pakistani military operations in the tribal areas, encouraged and heavily funded by the US, have met with violent resistance - including a rocket attack that killed four Pakistani troops last week. Despite the arrest of some high-level Al Qaeda operatives, Pakistan has so far failed to crack down effectively on the Taliban, which it sponsored until 2001. "For the Pakistanis or us to go in there and suddenly break the code is a lot to expect. It's just hard," says a senior Pentagon official.

Pakistani border guards erratically man hundreds of posts along the 1,519-mile frontier, but are poorly armed and unreliable because they and their families are local natives, US officials say. "There's a great deal of frustration with the border guards," says Lt. Col. Mike Howard, noting that someone shot at US troops from a Pakistani border checkpoint near Shkin in Paktika during a September firefight in which one of his men died.

It is these same forces that Colonel Howard must rely upon to set up additional checkpoints and block retreats when he is mounting operations in Paktika. Tenth Mountain troops do not cross the border, even in "hot pursuit" of the enemy, although elite US forces may have leeway to give chase a few miles into Pakistan. With Al Qaeda and Taliban sanctuaries in Pakistan beyond his reach, Howard's only option is to disrupt the fighters' infiltration via Paktika's mountain roads and impoverished, isolated villages.

Wearing a camouflage uniform without a flak vest, the Afghan militiaman tallies his losses against Al Qaeda and Taliban insurgents with a somber pride.

"We've had 20 or 22 AMF [Afghan militia forces] killed working with the Americans in the past two years," says Mohammad quietly. That's out of the 200 to 250 militiamen he says have joined US forces based at Shkin and Orgun in Paktika.

Interviews with a dozen militia members, interpreters, and other Afghans employed by US forces in Paktika suggest their jobs are as dangerous as they are critical to the US-led counterinsurgency. Indeed, the rate of AMF casualties described by Mohammad is far higher than that of US soldiers in Paktika.

"We are the main target of Al Qaeda," says Mohammad, who is troubled by what he calls the suicidal behavior of Al Qaeda fighters. "They hate us even more because without us, the Americans can't work here."

An AMF commander standing nearby agrees. "I've been working with the Americans five months, and I've been ambushed four times," he says.

Afghan soldiers like these bring speed, keen eyes, and local knowledge to US-led missions. Unburdened by heavy body armor and other gear, they can more swiftly chase guerrillas through the mountainous terrain. In a village they can also more easily pick out suspect individuals.

Yet the Afghans are highly vulnerable to retaliation for allying with Americans; all those interviewed said they had faced death threats.

In Paktika in recent months, Al Qaeda nailed "night letters" on compound doors warning that Afghans - along with their families - would be killed for working with Americans and setting up girls' schools. "I stayed up all night," says one interpreter, Ajab (not his real name) who received such a warning. He fears his neighbors could be guerrilla informants.

In response, US officers made a point of locating the homes of Afghan employees and gave them "SOS" flares to shoot if they were attacked. The US military also compensates the families of Afghans killed on missions. Ajab said his family received $2,400 after his cousin died in an ambush.

Despite their sacrifices, some Afghans feel their loyalty is doubted. "We can never ask [the US soldiers] where we are going. This shows the Americans have only a little trust in us," says Mohammad (a pseudonym). In Paktika, Afghan laborers have been warned by US officers that they will lose their jobs if coalition troops are ambushed in their communities.

Still, having cast their lot with "the helmeted ones," most Afghans say their only choice is to keep fighting. "We have to help the Americans," he says. "If the Americans leave Afghanistan, we will be in big trouble."