Distraught and weeping, the young woman called a hotline and described the note she had just found. It was from her brother. In it, he informed his family that he was leaving Germany to wage jihad. He could not lead a proper Islamic life in the West, he said. Shortly before, police had raided the family's home, adding to his sense that Muslims were being unfairly targeted.
On the other end of the phone was Daniel Koehler, then a counsellor for a pioneering program in Berlin called Hayat. Founded in 2011, the initiative grew out of long-standing efforts to dissuade people from following the path of right-wing extremism. Hayat instead focuses on counselling the families of those drawn to jihadi groups, with the goal of preventing further radicalization and even reversing it.
Mr. Koehler tried to reassure the woman. Over the next two years, he spoke with the family several times a week, often for hours, dissecting e-mails from the brother and crafting replies. "It's a bit like psychological warfare," said Mr. Koehler during a recent interview at a Berlin café. "You need to know what word to use, what provocation to ignore."
In this case, it worked: The brother left Syria, renounced violence and settled down in Egypt, where he is married, building a home and has two pets.
Mr. Koehler is one of a small number of specialists in a field that is increasingly in the spotlight. Governments around the world are searching for methods to prevent radicalization and the potential for homegrown terrorism. It's a task that's particularly urgent as jihadi groups, such as the so-called Islamic State, seek to attract recruits from other countries. More than 2,300 fighters from Western nations have already joined the conflict, according to expert estimates.
Europe offers some instructive examples for tackling the issue. In Germany, Hayat focuses on family counselling. In Denmark, a joint program between the local police and the city of Aarhus targets the individual at risk. Both have been inundated with international interest. Mr. Koehler has fielded inquiries from as far away as Australia; he is working with a nascent non-profit in Calgary to create a Canadian version of Hayat, while a British arm is expected to launch early next year.
Yet the field is also controversial. Experts have noted that there is little consensus on what deradicalization entails, which methods work best or what factors lead to extremist views in the first place. Others are uncomfortable with the focus on altering someone's political beliefs, often before there is any illegal behaviour.
When trying to dissuade people from extremism, "we haven't really come to grips with … what works and what doesn't work," said Rik Coolsaet, an expert on radicalization at Ghent University and a former adviser to the European Commission.
Mr. Koehler, 29, had his introduction to extremist thought early on. At his high school outside Berlin, young neo-nazis were their own subculture. "Like goths or punks," he recalled. "Neo-nazis, totally normal."
In 2010, he joined EXIT, a non-profit organization funded by the German government to tackle right-wing extremism. A year later, the group launched the Hayat program. (Hayat means "life" in Turkish and Arabic.) It employs three part-time counsellors and has worked on more than 100 cases since its inception in 2011, according to Mr. Koehler.
Most families reach the organization by calling a hotline set up by the German government, which then distributes the inquiries to a handful of programs, including Hayat. Sometimes, a son or daughter in the family is on the brink of going to Syria or Iraq – or sometimes the person has already left.
Initially, he said, families may be pleased with increasing signs of religious devotion among teenagers and young adults – eschewing drinking, for instance. But one technique used by radical groups is to initiate a deliberate conflict with a potential recruit's family. The normal parental reaction – anger – "is absolutely the wrong one in this case," said Mr. Koehler, who left Hayat in October and is now engaged in deradicalization research and training.
Families are informed at the outset that if a counsellor suspects some kind of illegal behaviour is inevitable, Hayat will contact the authorities with the family's knowledge. In his experience, Mr. Koehler said, by that stage, families aren't resistant to such steps. Most would rather have their son or daughter "alive in prison in Germany than dead in Syria."
In Denmark, the city of Aarhus has developed a model where the local police play a major role in co-operation with the municipality. When the program was established in 2007, social workers and teachers were skeptical, viewing the initiative as a fig leaf for intelligence gathering by the authorities, said Allan Aarslev, a superintendent in the East Jutland police.
Over the years, that distrust has eased, and social workers, teachers and community members have begun letting the program know about people in danger of radicalization. The police then invite the person in question to come for a completely voluntary interview.
"We're quite astonished. If we invite people in a frank and direct way, they come," said Mr. Aarslev.
"We give them the information we have and we express a sincere concern for what's going on in their life." Then they assess whether there is anything they can do to help the person, whether by connecting them with job training, a mentoring program, or educational opportunities.
Authorities in Aarhus also discovered that approximately 30 people from their city had left to fight in Syria as of the start of 2014 – and that the majority of them had frequented a particular mosque. In response, they met repeatedly with a group of the mosque's young members.
The message: If you do anything illegal in Syria, "our first priority is to make sure you're prosecuted when you get back," said Mr. Aarslev. "If you get back and want to get a grip on your old life, we can also help you to do that."
In 2014, only one person from Aarhus left for Syria, said Mr. Aarslev. Of the earlier group of 30, 10 are still there, five have been killed, and the rest have returned to Denmark.
Mr. Aarslev rejects criticism from some quarters that the methods in Aarhus are too soft. Passing legislation with harsher responses to potential Syrian fighters is "the easy thing," he said. "The tough thing is what we're doing – co-operating with minority groups."