BERMEL, Afghanistan - The Taliban took shelter in the U.S.-built school they blew up last year before they began the 400-foot climb, rockets in hand, to the American bastion on the hill.

Marshan, left, tells the story of an associate who was missing in Afghanistan and was later found with his head severed. (Photo: McClatchy Newspapers) Wrapped in space blankets - thin foil sheets familiar to campers - to avoid detection by the thermal imaging cameras in the U.S. outpost, they zigzagged up the escarpment. Troops at the base said insurgents had come right up on the helicopter landing zone, fired their rockets, then disappeared "like ninjas into the night."

Fortress Margha, with its grenade launchers and mortars sticking out from behind sandbags and bulletproof windows on three watchtowers, is a safe redoubt for the American troops stationed there. Within its walls, soldiers play ice hockey and video games that imitate guerrilla warfare.

For the Afghans who live in a medieval world of mud homes with interlocking walls in the valley below, however, reality is a reign of terror.

Taliban fighters rule the day and the night in the Bermel district, using threats and atrocities to control the civilian population, Afghans in the valley told a visiting reporter in interviews over two weeks. Accompanied by Arab and Chechen advisers, they behead civilians or sever their hands to force their cooperation. One of the latest Taliban edicts is a ban on cutting trees, so that insurgents can hide and lay ambushes for foreign troops.

From a distance, the U.S. base in Margha, occupied by a platoon from the 3rd Battalion, 509th Infantry Regiment of the 4th Brigade of the 25th Infantry Division out of Fort Richardson, Alaska, is a monument to a risk-averse, shorthanded American strategy in Afghanistan.

That could change with the arrival of an additional 17,500 American combat troops and of Lt. Gen. Stanley McChrystal, a hard-charging special operations man, to replace Gen. David McKiernan, who'd been faulted for failing to implement counterinsurgency strategy quickly enough.

The small U.S. base can be defended against as many as a thousand insurgents at once, confident American soldiers said. That sums up their dilemma, however: The fortress protects American troops, but it does little to help win a guerrilla war that's now in its eighth year and about to enter another violent summer.

The faltering U.S. and NATO efforts in eastern Afghanistan have in effect surrendered the countryside - village after village - to insurgent bands, many of them criminal gangs but some of them with weaponry and the backing of al Qaida.

The American troops descend from their bastion only on occasion, and there's no one to protect Afghan civilians from Taliban fighters, who collect a "zakat," or religious tax, from many residents in Bermel.

Living apart from the citizens they're charged with protecting isn't the only challenge to American forces. Afghans complain about errant U.S. artillery fire, which causes civilian casualties, and the constant infiltration of guerrilla bands from Pakistan.

If the goal of counterinsurgency strategy is to persuade the local population that the U.S. and its Afghan fighting partners are protecting them, it isn't working in this district, which sits opposite the al Qaida haven of South Waziristan in Pakistan.

Osama bin Laden declared "war on America" in 1998 at an al Qaida training camp not far from Margha in the neighboring province of Khost, and many Western analysts think that he's now hiding just across the border in Pakistan.

By night, the Taliban set up illegal checkpoints, where they rob people, residents said. If the residents are working with the Americans in any way, they're threatened or killed.

"They will take a person away, behead him and make a video, and sell it in the main bazaar in Bermel," an Afghan who goes by the radio name Nick Tajik said on the U.S.-financed "Radio Bermel." The radio is run out of FOB Boris, a nearby forward operating base that also functions as company headquarters for the 3-509.

Announcers at the small 50-megawatt station, which sometimes runs American military statements, said that one of their avid listeners, who sent in musical tapes and poetry, was executed recently behind a wall less than a mile from a U.S. military base.

Two announcers said they were shocked at the killing but that the Taliban had committed so many similar atrocities - "tens," they said - that it was hard to keep track of them all.

The American military, however, has only limited knowledge of Taliban atrocities in the Bermel district.

Lt. Col. Peter Minalga, 45, who commands the 3-509, which is deployed in parts of Paktika province, said he was aware of Taliban atrocities but that documenting them was difficult. Intelligence officers said that their unit, which arrived here two months ago, didn't discuss Taliban tactics with the last U.S. infantry units based in Bermel.

The American military doesn't post an infantry squad in the bazaar in Margha, and the U.S. military's own force-protection regulations often prevent junior commanders from leading squads of U.S. troops to protect Afghan citizens.

"The Taliban has finances and more tools than we do," said Islamuddin, another announcer on Radio Bermel. A mailbox for Radio Bermel, welded to a pole near the district market, has been destroyed at least five times. Sometimes, the would-be vandals just toss matches into the box to set the letters alight.

On an American foot patrol some 20 miles south of Margha, an Afghan who goes by the single name of Marshan begged American troops for protection.

"I've been here for two months. All my life I lived in Margha, but I can't go back because they will kill me," said Marshan, a former policeman.

An older man, leaning against a mud wall, sighed when he heard Marshan. "People want protection, but they have none," he said.

On another patrol just outside Margha in an 18-ton Mine Resistant Armored Personnel Carrier, artillery support Spc. Jesse Jones, 22, of San Bernardino, Calif., said the Taliban and their al Qaida associates were better guerrilla warriors than those he'd seen in Iraq.

"The enemy attacks are sophisticated and well-coordinated," he said. "They fight you longer and harder than the insurgents in Iraq. At the same time, when you pursue, they just disappear and blend back into the population."

Jones said that in a half-dozen attacks on his "route clearance" convoy - manned mostly by National Guardsmen from Virginia and California - insurgents had destroyed several hundred thousand dollars' worth of U.S. equipment. He added that his platoon hadn't been able to confirm that it had killed a single Taliban fighter.

In a subsequent sweep of Margha intended to capture known Taliban fighters who were living in the town, two American platoons entered the town as a blocking force. Two platoons of the 450 Afghan soldiers who are based at FOB Boris also took part.

On a hill overlooking the main market, Army National Guard Lt. Robert Bejarano, a city planner from Fresno, Calif., called for his platoon to halt Afghans on foot and in pickups as they rushed from the market.

Bejarano chuckled when he heard a radio intercept from an insurgent. "They are getting close," the voice said in Pashto. "There are three flowers in that vase." Bejarano said he thought that the insurgents meant that the Taliban had three soldiers in a house somewhere near where the Afghan soldiers were searching. No Taliban were found, however.

"If we want to get a grip on this town, we had better post American soldiers right down in the market," said Bejarano, waving toward the stalls.

Before the 3-509 arrived at Margha, the 101st Airborne Division had a platoon based here. Several children were accidentally killed by U.S. firepower, U.S. military officials in Paktika said, adding that the killings had become a permanent source of tension. Two American soldiers with the 101st were killed by a mortar round that hit their jeep as it as they defended a supply helicopter just outside the base last year.

U.S.-backed Afghan security forces from faraway tribes have added to the tensions. Some of them are from a far northern province that borders China. Others are from the province's small population of Tajiks, who've vowed revenge on their Pashtun neighbors because of atrocities committed when the Taliban were in power in Afghanistan.

"The local people say that the security forces insult them, insisting they have 'Taliban sandals' and tearing off their turbans," radio announcer Islamuddin said. "Sometimes they just cut their clothes with a knife and laugh."

He said that his station had attempted to expose the story by confronting the district sub-governor and the police chief.

A U.S. military intelligence officer working in the district said he was well aware of intimidation by Afghan security forces, in particular a local commander.

"When you (the United States) don't do counterinsurgency well, it is important to make others more afraid of you than the next guy can," the official said of the local warlord, whom American forces have come to rely on. The officer couldn't be named because he wasn't authorized to speak to a reporter.

"The other option when you don't do counterinsurgency well is to intimidate the population," he said. "But when it comes to that, you are really no better than the people you are trying to get rid of."