Despite Western efforts to counter extremism and terrorism recruiting, tens of thousands of foreigners have traveled to the Middle East to join groups like ISIS, The New York Times reports.
The number of people who have traveled to Iraq and Syria to join jihadist groups has doubled in the past year, according to The Times.
Intelligence analysts estimate that 30,000 foreigners have gone to the Middle East to try to join ISIS and other terrorist groups since 2011. A year ago, experts put that number at 15,000.
Western governments have been struggling to combat violent extremism in the social-media age. ISIS (also known as the Islamic State) has relied heavily on social media for radicalizing young people and enticing them to join their self-declared caliphate, the territory the group controls in Iraq and Syria.
These recruits sometimes convince family members and friends to come with them to live in what ISIS markets as an Islamic utopia.
"By now there is a 'network effect' where friends, family are bringing along other friends and family," Daniel L. Byman, a Georgetown University professor who is a fellow at the Brookings Institution, told The Times.
Western countries have launched their own social-media offensives to counter ISIS recruiting, like the Think Again Turn Away Twitter and Facebook accounts run by the US State Department, but foreigners are still pouring in to replenish ISIS' ranks as militants die in airstrikes and battles.
It's not all good news for ISIS. Even as new recruits join the caliphate, many others are leaving, joining the thousands of refugees who are flowing into Europe.
"They claim to create this Islamic utopia, and Muslims are fleeing in droves," Daveed Gartenstein-Ross, a counterterrorism analyst at the Foundation for Defense of Democracies, told Business Insider earlier this month.
And some analysts say the tide might be turning against ISIS. The strategic security firm The Soufan Group noted last week that "more people are visibly fleeing [ISIS] and the areas it controls than are flocking to join it."
"In an attempt to change the minds of people who would rather risk drowning than live in the Islamic State, the group has ramped up its propaganda efforts," The Soufan Group said.
"The scatter-shot nature of the Islamic State's recent messages — at times angry and denouncing refugees, at other times proclaiming the wisdom of staying in what the group sees as an Earthly paradise — shows the desperation of a group that resembles a pyramid scheme more than a government."
But once you're in the caliphate it's difficult to leave, as ISIS has a strategy to keep people inside its borders.
"It is in ISIS's interest to prevent a mass exodus by residents living in territory it controls, because this would undermine its image of a cohesive state-building project," The International Institute for Strategic Studies reported recently.
"The group has accordingly placed IEDs around entrances to cities it controls, such as Fallujah and Ramadi, to prevent escape, which simultaneously serve the larger purpose of preventing the [Iraqi Security Forces] from advancing."
The group is also having some money trouble — experts and caliphate residents told Newsweek recently that the group was struggling to keep its promises to its citizens for civil services. There's also a widening income gap between ISIS fighters and average civilians, which is breeding more resentment among those under ISIS control.
Some of the cash crunch comes from falling oil prices and airstrikes targeting oil facilities, and sources contend that ISIS spends more on weapons than on fulfilling the needs of the people living under its control. To make up for its reported drop in revenue, ISIS is said to rely more on taxation, the group's main source of income.
Nevertheless, foreigners continue to join the nascent caliphate.
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