“Usman has taken on some of the most hard-core, extreme cases that the U.K. has to offer, and he has a very good success rate at getting them back into productive roles in society,” said Douglas Weeks, a scholar who studies radicalization and provides unpaid advice to the Unity Initiative.
Most other counter-extremism or rehabilitation programs try to argue militants out of their ideology, often by disputing interpretations of the Quran. Mr. Raja works the other way around. He forms personal relationships with the young men at risk, usually spending five to eight hours a week, one-on-one, with each, sometimes meeting five days a week. He builds their sense of engagement in a community, and then watches for the ideological or religious arguments to fall away.
“That is where the mixed martial arts come in,” Mr. Weeks said. “It gives him street cred, and a starting point to have some of these conversations.”
Mr. Raja might pass for one of convicts he works with. He shaves his head, trims his thick beard back to his jawline and wears a braided leather cord close around his neck. A silver ring on his right hand is shaped like a talon, to double as a weapon.
He speaks in a thick East London-Cockney accent, and his words gush out in a jumble of enthusiasm, hopping from musings about the human condition to reflections on the history of Islam and anecdotes about the many jihadists he has known.
Like Ali Beheshti, a former top leader of a London-based extremist group, Al Muhajiroon. Mr. Beheshti once set fire to the house of a publisher who produced a novel about the Prophet Muhammad. That earned him four years in Belmarsh prison, which is where Mr. Raja first encountered him.
“Ali has a tattoo on his forearm that says, ‘Only God can judge me,’” Mr. Raja said. Most Muslims scholars say Islam forbids tattooing, but militants often pick and choose the scripture that fits their purpose.
Mr. Raja met with Mr. Beheshti five days a week for a year and a half, trained him in fighting and eventually brought him out to the gym to spar with a white British soldier.
“From Ali’s point of view, ‘This is one of the guys I have been preaching to kill for years,’” Mr. Raja recalled. But the soldier told Mr. Beheshti, “Congratulations, we are really proud of what you are doing.”
Now, Mr. Beheshti volunteers to help the Unity Initiative, although he is not yet ready to help out the police. “He is still street-respect oriented in that respect,” Mr. Raja said.
Wahabi Mohammed, who was convicted in 2005 of withholding information about his brother’s failed attempt to bomb the London Underground, said in an interview that when he was imprisoned he met with numerous counselors who tried to argue him out of his extremist convictions.
“I felt like a guinea pig,” he said. “I gave them two hours a visit, and it never went further than that.”
He had heard from other prisoners about Mr. Raja’s cage fighting before he met him. “In prison, it definitely helps,” Mr. Mohammed said. “It says: ‘I am not just somebody from a university. I am from the streets, my perspective comes from a valid experience.’”
So he was surprised to get a hug from Mr. Raja the moment they met, in 2010, in a room in the prison. “I wasn’t sure how to take it, but it felt nice,” Mr. Mohammed recalled.
They began talking as peers, about the shared problem of “how to be a Muslim, and how do you fit in the modern world?” Mr. Mohammed recalled.
Mr. Mohammed was released on probation in 2013 and now works in construction. He lives with his wife and five children in West London, and he, too, helps the Unity Initiative.
Mr. Raja is the son of Pakistani immigrants who had an arranged marriage in Britain when his mother was only 15. They were soon divorced, and Mr. Raja was raised by his single mother in a predominantly white, working-class town near the gym, in an area dominated by the British army base in Aldershot.
He learned his first lessons about fighting by brawling with the soldiers’ sons, who used racial slurs about Pakistanis. By the mid-1990s, Mr. Raja was making a name for himself as a fighter and trainer in the gyms of East London, and young British Muslims hoping to join the jihad against the Bosnian Serbs sought out his coaching. Mr. Raja thought about joining them but instead became a disciple of a Malaysian Muslim scholar who preached a more pluralistic and tolerant understanding of the faith.
The American-led wars in Afghanistan and Iraq in the early 2000s furnished ample new material for jihadist preachers all over London, and Mr. Raja fell into a kind of voluntary social work. He mediated sectarian feuds, and befriended a small mafia of Kurdish immigrants who practiced what Mr. Raja called “gangsterized Islam,” justifying their street crimes by targeting non-Muslims. He tried to convince them that their faith required decency to all.
Mr. Raja’s street demeanor and liberal theology caught the attention of the Quilliam foundation, a counter-extremism group founded by British Muslims that was supported with millions in grants from the British government. Hired to run outreach programs, he quit after two years, finding the group too removed from the streets.
One evening in 2008 an officer from the Central Extremism Unit of the British police called to talk about Yassin Nassari, a British Syrian who had been convicted of terrorist plotting after being apprehended at Luton Airport with plans on his hard drive to build a rocket.
At this point, Mr. Nassari was up for parole, but he was refusing to talk to the government’s de-radicalization specialists. He had heard of Mr. Raja, however, from friends who had trained with him. He was the only one Mr. Nassari would work with, the officer said.
Mr. Raja started filing papers to create the Unity Initiative that night. He then immersed himself in Mr. Nassari’s life and trained him in mixed martial arts fighting. Mr. Nassari now works at a charity providing support for other Muslim ex-convicts.
Nine years after that call, Mr. Raja was climbing back into the ring again, in part to keep up his cage-fighter mystique.
His sparring partner was Lyubo Kumbarov, a famed 33-year-old Bulgarian fighter and instructor. Within two seconds, he rammed his bullet-shaped head into the side of Mr. Raja’s neck, picked him up and spun him in the air like a top and threw him crashing down flat on his back.
“Make sure you note that Lyubo is a wrestling master,” Mr. Raja said, struggling to his feet and catching his breath.