With the world still reeling from last Friday's Islamist terrorist attacks in Paris that killed 129 people, foremost in many people's minds is whether Islamist extremists like the "Islamic State" (IS) will strike again soon and if so, where. A report from the Washington-based New America think tank entitled "ISIS in the West: The New Faces of Extremism" provides some clues. Of the estimated 4,500 Westerners that have joined jihadi groups in Syria and Iraq, the study looked at 474 individuals from 25 Western countries to develop a clearer picture of who they are and why they go.

One striking statistic is that women made up around one in seven of the Western jihadists. According to Peter Bergen, the report's co-author and New America's vice president, "there is an unprecedented number of women going there, and some of them are quite well-educated." The average age of female recruits was just 21 years, compared to 25 years for the Western males who have gone. About one in five recruits were teenagers.

Just as remarkable is the very high death rate among Western recruits. Nearly 40 percent of the sample study has been reported killed, including 6 percent of the females, even though IS maintains that women are not supposed to be placed in combat zones. "It is as much a graveyard as a launch-pad for attacks," Bergen told DW.

Country of origin

As for the country of origin of the Western jihadists, a disproportionately high number are being recruited in Belgium, France and the United Kingdom. These countries feature top of the list of the individuals analyzed for this report and of Western governments' estimates of how many of their citizens have joined jihadist groups in Iraq and Syria. Last Friday's attacks in Paris are thought to have been perpetrated by a cell composed mainly of Belgian and French nationals.

Bergen highlighted France's failure to assimilate its Muslim population as a major concern. While just 8 percent of France's citizens are Muslim, around 70 percent of its prison population is Muslim, he noted, adding "they are highly disadvantaged, criminalized, ghettoized." But not all Western jihadists fit this underprivileged profile. "It does depend on which country you are talking about," he said. For instance, Mohammed Emwazi, the British citizen of Arab origin who became known as 'Jihadi John' after he featured in several IS beheading videos, came from a middle-class background and was college-educated.

It is clear there are far fewer American than European jihadists in Syria and Iraq. Less than 6 percent of Westerners studied came from the US. According to Douglas Ollivant, Senior Future of War Fellow at New America, this is due mainly to the US having a better scorecard than Europe for integrating its Muslim populations. "We don't have huge reservoirs of second, third and - in the case of France and the Algerians - fourth generations of North African or Middle Eastern residents who are totally unassimilated," Ollivant told DW.

Better integration

Bergen noted that the average income of Muslims in the US "is the same as any American," whereas in many European cities, Muslim communities remain an economic underclass. As a result of being better integrated, "the threat to the US by IS is really, really small," he said.

Family ties are another important factor behind jihadists' success in attracting so many Western recruits. Around a third of the Westerners who went to Syria or Iraq have a family member who already is fighting for a group there and many are entering into marriages after they arrive. Ollivant added that sometimes they go as an "anti-bourgeois statement - to shock their parents."

The power of jihadist media cannot be underestimated either. IS has been especially effective at marketing itself as an appealing brand. The group's highly-professional videos and publications - such as the online English-language magazine Dabiq - depict an "illusion of success," said Ollivant. Like any good recruiter, "they know how to tailor the message to whatever the recruit is looking for."