Fighters join the so-called Islamic State group for myriad motives, but one big reason might be the lure of one of the most basic human desires: sex.
“The offer of access to sex is part of the Islamic State's recruitment strategy,” said Jytte Klausen, a professor at Brandeis University and the founder of the Western Jihadism Project which monitors Islamic State activities.
“It has to be assumed that it works. Many young and not-so-young men in the Middle East and Africa, and beyond, live under circumstances where it is not possible for them to set up independent households and family lives," Klausen said.
In a gruesome example of just how seriously the Islamic State [IS] group takes the availability of sex as a lure for would-be fighters, the group recently published an online guide on the treatment of sex slaves.
According to a translation from Middle East Media Research Institute (MEMRI), a U.S.-based non-profit monitoring militant online activity, some of the rules in the guide include permitting men to engage in sexual intercourse with “captive” females, permitting the sale of a female captive, and perhaps most chilling, permitting a man “to have intercourse with the female slave who hasn't reached puberty if she is fit for intercourse.”
Klausen said sex and forced marriage are Islamic State recruiting tools. She cites poverty, displacement and the breakdown of traditional capabilities for the arrangement of marriages to having contributed to the “creation of hundreds of thousands, perhaps even millions, of transient single men.”
“Revolutions have always drawn on such men for fuel,” she said. “The Islamic State clearly hopes to attract them as part of its colonization strategy.”
Mia Bloom, a criminology professor at the University of Massachusetts Lowell's Center for Terrorism and Security Studies, said the sex lure is more than a recruiting tool.
“A lot of the fighters know that if they go to [IS], they are guaranteed a wife, or more than one,” she said. “It’s also about retention so they don’t leave.”
Bloom added that recruitment consists of a combination of “worldly and other-worldly incentives.”
According to a September United Nations report on human rights abuses by Islamic State fighters, it “received a number of reports that an office for the sale of abducted women was opened in the al-Quds area of Mosul city.”
“Women and girls are brought with price tags for the buyers to choose and negotiate the sale,” the report said. “The buyers were said to be mostly youth from the local communities. Apparently [IS] was ‘selling’ these Yazidi women to the youth as a means of inducing them to join their ranks.”
Women, girls taken captive
The Yazidi minority of northern Iraq came under furious attack by Islamic State militants in the summer, with thousands of women and girls reportedly taken captive.
Matthew Barber, a doctoral student at the University of Chicago who is studying the Yazidi, was in Iraq when the community was besieged. In interviews with survivors, he said he discovered that thousands of women and girls had been taken prisoner by the Islamic State group.
In an interview posted on YouTube, Barber said the capture of so many women and girls was no accident.
“Over time, it became clear that it was a sexually motivated campaign to take large numbers of concubines, to take Yazidi women and place them in jihadi homes basically as domestic servants/sex slaves,” he said.
He said there were credible reports that the first wave of Islamic State fighters attacking the Yazidi came with empty trucks specifically to ship off women and girls.
The Islamic State group first denied these reports but later said they were true and provided what they said was religious justification for their actions.
That justification, according to Barber, is that they believe that having justified and available sexual alternatives to their wives will allow them to maintain sexual purity.
“What is clear is that fighters are rewarded for their efforts in jihad with women given to them as gifts by the IS,” he wrote in an email.
The practice is not isolated to northern Iraq.
'Sold off as slaves'
Writing in the Wall Street Journal, Haleh Esfandiari , the director of the Middle East program at the Woodrow Wilson International Center for Scholars, said that in Islamic State-occupied Syria, there was “a photo of a line of women, covered from head to toe and tied to one another by a rope, as they were being led to a makeshift slave market.”
“To the men of [IS], women are an inferior race, to be enjoyed for sex and be discarded, or to be sold off as slaves,” she wrote.
Numerous reports indicate Islamic State fighters operate brothels in Syria and Iraq.
"Some [women are] sold to individual men, others are kept by [IS] in rest houses and face multiple rapes by fighters returning from the battlefield," wrote Valerie Amos, the United Nation's Undersecretary-General for Humanitarian Affairs and Emergency Relief Coordinator, in a report earlier this month.
She warned more violence against women was likely.
"Recently, Kurdish refugees from Kobani reported the capture of young girls by [IS] for sexual purposes,” she wrote. “Girls as young as twelve.
"Reports of early and forced marriage are also on the rise. This is in part due to a depletion of family resources, and more recently because parents are terrified of their unmarried daughters being forced to marry [Islamic State] fighters in areas under their control," she said.
And for women and girls who refuse to become sex slaves, the consequences are brutal.
The Jerusalem Post reported this week that Islamic State militants killed 150 women and underage girls for refusing to perform sex acts with the fighters.