The war being waged across Iraq and Syria in the name of an Islamic caliphate has rocked the region and shocked the world beyond. Never more than this week when James Foley was murdered in an archaic act of barbarism. Although the killer's identity remains wrapped inside the black face mask he wore as he beheaded the American journalist, he is widely believed to be British.

That would make him one of some 500 British citizens thought to have traveled to Syria and Iraq to join the ranks of the "Islamic State" (IS) and part of Europe's largest national supplier of foreign fighters.

But what makes Britain's young more likely to lend their names and their lives to the cause than their contemporaries in other, similar countries?

Matthew Francis of Lancaster University's Radicalisation Research project says it is hard to find a common denominator, and that it doesn't make sense to look at predictors such as geography, education or affluence. "They come from all over the UK, and many are well-educated people who went to university," he told DW. "We know of one man from Cardiff who had aspirations to become the future British prime minister."

IS fighters have captured large areas of Iraq and Syria

Francis says recruiting foreign fighters is all about creating the right conditions, and that primarily means making people believe they are part of a transnational community that is under threat.

"When Western governments fail to arm the Free Syrian Army, that becomes conflated into the West versus Muslims, and that is what we heard in the video yesterday," he said.

Finding the weak spot

Erin Marie Saltman, senior researcher at the Quilliam Foundation and co-author of the foundation's recent report "Jihad Trending" says that while there is a tendency to make sweeping generalizations, there are various factors that drive young men, and to a lesser degree women, into the pockets of extremist groups.

"What we can say is that the target audience is younger males, and there tends to be a connection with second or third generation Muslim immigrants, but even then, there are cases where there has been no Muslim background and people have converted."

She says many recruits are united by their desire to feel special in a world where affluence and greatness look set to elude them. And radical Islamist groups tap into their desires and sense of despair.

Journalist James Foley's killer is believed to be British

"They play on it, and invite people to be a part of a group that is strong and offers adventure and the chance to change the world."

Potential recruits are often picked up at universities or in prisons, so in close-knit communities where there is the potential for the domino effect. But once the first off-line contact has been made, they are taken online where they are exposed to a wealth of literature and tools which assist in what Saltman describes as the "radicalization process."

Social media and cultural understanding

Ross Frenett from the London-based Institute for Strategic Dialogue says there is a pre-existing extremist underground in the UK, which has been electrified by the conflict in Syria, and agrees that recruitment success relies on factors such as the search for identity. But he also says the rise of social media has played a role in encouraging young men to sign up to the Islamist cause.

Experts say 'Islamic State' recruiters know how to manipulate young Europeans into joining their fight

"People can talk directly to fighters in the field, which means they are in touch with the conflict in a way we have never seen before, not even in Iraq in 2006."

But Anthony Glees, Director for Security and Intelligence Studies at the University of Buckingham believes the problem is rooted in cultural understanding.

"Our policy of multiculturalism has given men of religion, who are actually men of politics and extremist politics, camouflage to reach out to young people, and our deep commitment to free speech has been perverted by them as a means of radicalizing people," he said.

Finding a solution

In a statement issued on Thursday (21.08.2014), Prime Minister David Cameron said Britain would take a series of measures including removing passports from suspects contemplating travel.

But in a liberal state where people are innocent until proven guilty, that could be a difficult move.

Given the difficulties in isolating clear common reasons for people to turn to radical Islamist groups, Francis says it is more useful to look at engagement and recruitment. "If we understand that, we can disrupt it," he said.

Saltman says there is an evident lack of strong counter narratives, and that it is time for the silent majority to become more vocal in explaining why the "Islamic State" is not a healthy group, why what they are preaching does not have its roots in Islam and why it is socially wrong. "We need strong voices from activists and community and religious leaders," she said.