KHASAVYURT, Russia -- The slender man of 22, a former guerrilla fighter, was making another hangdog, penitent appearance at the behest of city officials here. It was brainwashing that led him to take up arms against the state and "go to the forest," he said, and his sincere desire was to forget that it had ever happened.
Most of the time, people like this young man, Dzhabrail Altysultanov, do not come back alive, the deputy mayor of Khasavyurt, a city near the Chechen border, acknowledged matter-of-factly, as a waitress brought a steaming platter of roasted meat. If Mr. Altysultanov had not surrendered, the official said, "they would have had to gather him up in pieces." The younger man looked down at his plate.
The six-month sojourn of the suspect in the Boston bombing, Tamerlan Tsarnaev, in the Russian territory of Dagestan last year has drawn unusual attention to the low-boil guerrilla warfare of the North Caucasus. A picture has come together of Mr. Tsarnaev as an outsider feeling his way around the edges of an insurgency that looked very different from the stories of partisan fighting that he had heard growing up among Chechen refugees.
Investigators are pushing to better understand what Mr. Tsarnaev was looking for when he traveled here. But what he found was a shadow war that takes place around the edges of normal life, hidden in plain sight.
Young men vanish from their homes, only to reappear in tallies of the dead after scorching counterterrorism operations. Though the number of fighters is probably no higher than a few hundred, law enforcement officials say, it is backed by a sprawling and invisible support network -- thousands of ordinary people, even police officers, who assist them, out of fear or sympathy. It is a society engaged in an intimate tug-of-war over young men who slip easily into the ranks of the insurgency.
"You want to talk about Tsarnaevs," said the mayor of this city on the Chechen border, a barrel-chested local strongman named Saigidpasha Umakhanov. "Do you know how many Tsarnaevs we have?"
Mr. Umakhanov, a wrestling coach, knows just how close the combatants in this war are.
The guerrillas recruit athletes, and five of his star pupils have risen to become insurgent commanders, or "emirs." One of his deputies was forced to resign last year after his son was accused of aiding an armed group. The fighters visit Khasavyurt to hunt down city police officers -- 36 have been killed since 2009 -- or to slip flash drives with videotaped messages into the mailboxes of officials or businessmen, asking for money, lest "God punish you with our hands."
Last October, someone came for the mayor himself. A bomb went off beside his motorcade, leaving behind a crater 3 feet deep and 10 feet wide.
The state answers with its own thunder. In April, armored combat vehicles and masked commandos surrounded the mountain village of Gimry, a stronghold of Islamism and defiance to Russia, and ordered women and children to evacuate. Troops shelled a neighboring gorge and then used ropes to haul out the bodies of three suspected militants. When residents were allowed to return a week later, many homes had been ransacked, some reduced to rubble.
In Dagestan, with a population of nearly 2.9 million, about 350 people were killed in fighting here in 2012, of which two-thirds were militants and one-third police officers, according to the news service Caucasian Knot. The message from the authorities is clear: Once a young man has taken part in an attack, he is unlikely to live long.
"They cannot return -- there is no road back," Mr. Umakhanov said. "That is the problem."
It is against this backdrop that Mr. Altysultanov is trying to find his way "back from the forest," as they say here.
Sitting before a banquet, apparently too nervous to eat, he told the story of how he and other athletes from his gym had fallen under the influence of Rustam Khamanayev, a charismatic older athlete who called himself "emir of the Aukhovsky jamaat." One day, they were told to report to an abandoned warehouse, swapped their track suits for camouflage, received automatic weapons and were loaded into the back of a van headed for a camp.
"I can say, for myself, that I had a fantasy of holding a gun in my hand," Mr. Altysultanov said softly. "Because Khamanayev said so, I thought that a Muslim must live in Shariah state. This was the goal." The emir demanded elaborate shows of respect; the fighters could not turn their backs to him.
Mr. Altysultanov said he began to miss his family. It was such a hard time, he said, "Even thinking about it, my mood is spoiled."
Dagestan's push to rehabilitate guerrilla fighters was itself an experiment, undertaken as Dmitri A. Medvedev, then the president of Russia and now the prime minister, was testing softer approaches to the stubborn violence of the Caucasus.
Analysts have pointed out problems with the initiative -- for instance, the humiliating requirement that each man confess his mistakes and condemn the insurgency before television cameras, for propaganda purposes. Law enforcement officials resisted the program as excessively lenient, and questioned whether the men who surrendered really repented, according to a report by the International Crisis Group.
But the most serious obstacle is that young people do not trust the police to guarantee their safety, said Sapiyat Magomedova, a Khasavyurt lawyer who represents people accused of aiding insurgents. She scrolled through photographs of clients who were beaten in police custody, as officials sought confessions or bribes. She herself was beaten unconscious in a police station in 2010, when she was trying to get access to a client.
"Who is pushing them into the woods? Who?" she said. "It is those same officers. Their outrages send these people into the woods -- what they do to their relatives, the fact that they torture them, they mock them. They leave angry, and they go to the forest."
"The population doesn't know who to be afraid of," she added. "The police, or the fighters."
In Khasavyurt, a handful of mothers and fathers have tried to thrust themselves into that gap, walking the forests at night to search for their sons, and warning that the state's hard-line approach was driving young men deeper underground.
Seven men left an armed band last fall, including Mr. Altysultanov, who had disappeared from his home three months earlier. At a public hearing, all seven gave ritual apologies and tried haltingly to explain their reasons: unemployment and an inability to pay bribes for education. One said he had been led to believe that he would go straight to heaven if he died in the name of Islam.
These days, Mr. Altysultanov works in his uncle's construction business. "He is my emir now," he said, with a wan smile.
It was impossible to know, watching him and the deputy mayor, how much had really been forgiven and how much forgotten.
When he crosses paths with the other men who were with him in the guerrilla unit, he said, they do not talk about what they did together. They are right to be ashamed, said Khaibulla Umarov, the mayor's deputy for social safety and ideology.
"They want to cut it out of their lives," Mr. Umarov said. "Those three months will follow them for the rest of their days. Their kids will be playing, and other kids will tell them, 'Your father was one of the forest people.' "
This article originally appeared in The New York Times.