The teenage insurgents spend their days learning to make shoes and bookshelves, listening to religious leaders denounce the radical interpretation of Islam they learned as children.

But when they return to their cells at Kabul’s juvenile rehabilitation center, the boys with wispy beards and cracking voices talk only of the holy war from which they were plucked and their plans to resume fighting for the Taliban.

“They bring us here to change us,” said Nane Asha, in his late teens. “But this is our way. We cannot be changed.”

As the Taliban presses its efforts to recruit teenage fighters, Afghan officials and their international backers have crafted a program to reintegrate the country’s youngest insurgents into mainstream society. But that ambition is coming up against the intransigence of the teens, who say they would rather be on the battlefield.

“We’ll fight against America for a thousand years if we have to,” said Ali Ahmad, 17, sitting at a desk that has hearts and Koran verses scratched in the wood. “Jihad is the duty of every Muslim.”

Before joining the insurgency in their early teens, the fighters were students, part-time shopkeepers and farmhands, mostly living in the Pashtun-dominated regions of southern and eastern Afghanistan. Some say their parents supported the decision to take up arms. Others left home without warning, disregarding the wishes of relatives and heeding what they call a religious and moral obligation.

Here at the detention center, they live alongside a large group of teens found guilty of crimes unrelated to terrorism. Often, young Taliban members are described as desperate rather than ideological, but the 30 teenage fighters here appear undeterred and unrepentant, and they vow strict adherence to the group’s creed.

“We tell them, ‘You could be a mullah or a tailor or a carpenter.’ But they come here with a misinterpretation of the Holy Koran stuck in their mind. It can be hard to erase that,” said Shah Abbas Bashardost, who works with the boys.

“If we can’t get through to the kids, who can we rehabilitate?” Bashardost said.

Reintegration is at the heart of U.S. and Afghan government strategies to wind down the war, with schooling and employment being offered to coax fighters away from the insurgency. Juvenile offenders seemed a sensible starting point in that campaign, because many assumed they would be easier to win over than adults who have spent years, or even decades, waging war.

In the next few years, reintegration programs such as the one at the Kabul juvenile center — which is run by Afghans but bolstered by foreign supporters, including the United States — are expected to take shape at prisons across the country. But the disappointing results at the Kabul facility reflect the challenges facing the campaign.

The experience of boys such as Asha and Ahmad suggests that after years of religious schooling and combat, the draw of war might be too strong to overcome.

An early start

The Taliban visited Asha’s school when he was about 13, preaching the evils of American interlopers and the value of violent jihad. Asha approached the speaker after the sermon ended. “How can I join you?” he asked.

Within a few weeks, Asha was enrolled in a six-month training course, learning how to fire a Kalashnikov and to connect a nest of wires and explosives that could take out a U.S. tank. He studied the material obsessively.

“I would be on my motorbike, but I’d be going over the information in my head: how to make the bomb work, how to connect all the parts,” he said.

At the end of the Taliban course, Asha, like most of the other young fighters at the rehabilitation center, was tested on his knowledge. He placed first in his class of 37.

“My parents were very proud,” he said.

Then Asha put his new skills to work, scurrying across Helmand province to lay a variety of explosives in areas where foreign troops were likely to travel and watching from a distance as his handiwork sent plumes of smoke, dust and shrapnel into the air.

Sometimes, he said, he fired on the troops who emerged to tend to the wounded. Sometimes, he got too close, and pieces of hot metal punctured his skin, leaving scars.

Asha was rising through the Taliban ranks, accruing subordinates and ammunition, when Afghan police stopped him in Kandahar last year, recognizing his face from a photo of suspects.

Bone scans of inmates

Asha told interrogators that he was 16, even though he thinks he is several years older, because sentences are halved for juveniles. Rather than serve time in conventional prisons, teenage insurgents are sent to minimally secured rehabilitation facilities, which look more like high schools than jails. Afghan authorities have taken to performing bone scans of young inmates to ascertain their ages, knowing that many lie.

In May, the country’s intelligence agency paraded five boys ages 11 to 17 in front of reporters, photographers and cameramen in Kabul. The boys were among 400 juvenile fighters arrested by the intelligence agency in the past two years; many more have died in battle.

On stage, the boys told reporters that they wanted to divorce themselves from religious extremists and return to their families. They seemed ripe for exactly the kind of services offered by the rehabilitation program.

But at the Kabul center, detainees call Taliban members on borrowed cellphones to reassure them that their commitment to jihad has not weakened. Taliban commanders promise to reward the boys for serving prison sentences, the detainees said.

Religious officials handpicked by the government visit several times per week, charged with teaching the children a more moderate interpretation of Islam. Three social workers aim to dull the luster of the insurgency, promoting alternative careers.

In July, the Italian Embassy inaugurated a gym and computer lab at the facility. The United States assigns its military officials as “mentors” to advocate for some of the inmates and provide mattresses and school supplies to the facility.

Over the next four years, the United States has said, it will “support de-radicalization teams, reintegration efforts, and rehabilitation programming for prisoners,” particularly in the south and east, according to a plan released this year by the U.S. Embassy. American officials acknowledge the rehabilitation center’s shortcomings and say they plan to increase training for the facility’s employees and provide additional vocational instruction for inmates.

Grand ambitions

For now, the juvenile center’s practices do not always match its lofty ambitions. Several days a week, when religious officials are unable to teach Koran classes, Asha leads the group instead. While a group of boys told an American reporter that their ultimate goal was “to kill you people,” a social worker within earshot appeared unfazed, saying nothing.

“How much progress are these centers really making?” said Latifullah Mashal, a spokesman for Afghanistan’s intelligence service.

Meanwhile, officials at the juvenile center are looking for reasons to be hopeful — or, short of that, to explain their lack of success.

“We are concerned about whether they will go back to the Taliban,” said Aziza Adalatkhwah, the center’s director. “But, ultimately, it depends on the child and on how much they love their county.”