When they arrive they are usually quickly married to a fighter with the Islamic State in Iraq and Syria and begin a strictly controlled domestic life of child-rearing, cooking and cleaning.
Much of this indoctrination takes places through social media, including on Twitter, as the teenagers speak with female recruiters who have already made the journey and offer advice on what to bring and who to contact once they arrive in a neighbouring country like Turkey.
"It offers them a sense of adventure, which is not only the voyage — which is an allure itself — but also these romantic notions that upon arrival you will be paired," says Erin Saltman, who leads the women and extremism program at the International Strategic Dialogue in London.
Six young Quebecers left Canada in January to join militants in Syria, including at least two women. Three British teen girls flew to Turkey last week in an apparent bid to join ISIS.
Although some women, particularly those from the minority Iraqi Yazidi group, are sold into sexual slavery, young Western women are treated differently, Saltman says.
"But it's not to say that once they're married husbands aren't abusive or forcing themselves on them," Saltman says.
They are heavily restricted and unable to leave the house without their new husbands. They have little chance of escape, she says, many having turned over their passports when they arrive as a sign of allegiance to ISIS.
The International Strategic Dialogue released a report last month on the radicalization of western women, which was based primarily on statements made through social media accounts.
It found that the women who travelled alone appeared to be motivated by three primary reasons: the perceived oppression of Muslim people, a desire to create an ideologically pure state and a personal religious duty to assist in the process.
Saltman says about 550 women from western countries have travelled to ISIS-controlled territories, including about 70 from France and another 50 from the U.K.
Although some young women may be shocked at the living conditions, particularly in war-torn areas, most young women who have become radicalized to the point of leaving their families and homes have a pretty good idea of what they are getting into, she says.
"They're not just wilting violets," Saltman says.
Mia Bloom, author of Bombshell: Women and Terrorism, says online recruiters will tout the alleged benefits of living in ISIS territories, claiming they will become part of a sisterhood with many like-minded friends.
"They're trying to sell this idea that it's a very idealized utopia," she says.
The online recruiter will often discredit the reported atrocities of ISIS by saying that the media is biased.
"Like the sexual pedophile, they are creating rapport, building trust, creating an environment of secrecy, you know, 'let's not tell anybody,'" says Bloom, who also teaches security studies at the University of Massachusetts, Lowell.
They can also provide tips on how to leave the country, including what to pack, what to wear, and how to avoid suspicion with security, as well as sometimes providing financial help for purchasing plane tickets. Similar information can also be found on websites.
CBC News reported earlier this week that one young woman travelled to Syria after apparently becoming radicalized. Her sister says she was recruited under the guise of an online class to study the Qur'an taught by a woman in Edmonton.
Not told specifics
ISIS has become particularly adept at using social media as a recruitment tool, particularly for young people, experts say.
In Spain, four people were arrested Tuesday in what police say was a sophisticated social media campaign designed to lure women to join extremist groups like ISIS.
Bloom says the women are usually told to simply fly to a country like Turkey and then to get in contact with a particular person who can ultimately take them to ISIS-controlled territories.
She says the women are intentionally not told about specifics of the plan so that if they are caught in transit they can't provide detailed information on the route they would have taken to get into Syria.
Three teenagers from Denver were arrested last October in Germany, for example, in an apparent attempt to join ISIS militants.
Young women are specifically targeted largely so that they can be married off as a reward to extremist fighters.
"It's a way in which you ensure these foreign fighters aren't going to turn around and leave if they get disillusioned or they get sick and tired of living in Syria," Bloom says, "because they know they have a house, the wife, the kid, they're sticking around."
It is also part of state-building efforts on the part of ISIS, Saltman says.
"Now that they have this territory, the secondary aim is to actually build a state and you need women to create the second generation of this state," she says.
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