Editor’s Note: As police tracked down the members of the cell that brought terror to Spain on Thursday, the names that surfaced were once again, predictably, all men, and mostly young ones. That’s the classic pattern with jihadis. But many counterterrorism experts see a new threat rising—what French criminologist Alain Bauer calls “the feminization” of the so-called Islamic State, which is under siege in the Middle East and looking to intensify its campaign of gruesome retaliation in the West.

Although in relative terms the percentage probably remains small, says Bauer, “You never had so many women.” Just a year ago in France, for instance, a cell was broken up composed entirely of women who had plotted to set off a car bomb near the Cathedral of Notre Dame de Paris, a prime tourist destination fraught with religious significance as well.

In the battlefields of the Middle East, meanwhile, according to French security sources the women of ISIS are targeted right along with the men by European commandos on hunt-and-kill missions. Indeed, there is an old tradition among the European services—“shoot the women first”—documented in detail by British journalist Eileen MacDonald in 1991 after extensive research on the female terrorists among the radical left and the Palestinians. As one senior security expert told MacDonald more than 25 years ago, “Women terrorists have much stronger characters, more power, and more energy than men. There are several examples where men who have been cornered have waited a moment before they fired, but the women shot at once.”

Mia Bloom has studied closely the motivations and impact of women who have carried out suicide attacks from Russia to Sri Lanka as well as in the Middle East. “Women bombers… tend to be more successful than men,” she wrote in her 2011 study, Bombshell: Women and Terrorism. The message their attacks bring is distinct from the men: “Terrorism is no longer a fringe phenomenon and the insurgents are all around you.”

But why on earth would women want to join the ranks of the dogmatically, cruelly, and often violently misogynist ISIS “Caliphate”?

The following study by Anne Speckhard and Ardian Shajkovci of the International Center for the Study of Violent Extremism (ICSVE), based on exhaustive interviews with dozens of women and men who have been involved with ISIS, and then turned away from it or against it, answers critical questions at a critical time about the feminization of ISIS.

— Christopher Dickey, World News Editor

BRUSSELS—When she was just 19, and a convert to Islam, Laura Passoni was abandoned by the father of her young son. Determined to deepen her expression of faith and in hopes of attracting a man who would keep his commitments to marital and family life, Laura responded by putting up a more devout Facebook profile, and very quickly she was contacted by an ISIS recruiter.

He promised her a man who would never leave her, a home in Syria, training as a nurse, and a good school for her toddler. Broken-hearted and wanting to believe, Passoni agreed to embark on a journey to the Islamic State. To evade detection, she and her toddler and the man she had chosen with the advice of the recruiter traveled by land to Venice and then took a cruise ship to Izmir, Turkey. From there they continued in a taxi to Gaziantep and crossed from into to Syria to join ISIS. Passoni thought of the cruise as a romantic time in which she consummated her marriage to a near stranger.

Her induction into the Islamic State was far from what she had envisioned, however. She ended up staying in a “sisters’ house” while her husband went off to receive sharia training and become a fighter. She was invited as well to serve ISIS as an internet seductress or a member of the morality police (hisbah). She declined both offers.

Passoni became deeply disappointed as she found herself confined at home while her husband was away battling for the group. None of the ISIS recruitment promises materialized—no nurse training and no riches. She found herself having to let her son play alone unsupervised outside or go with “the brothers,” other Islamic State fighters to the mosque. Witnessing how young the boys were that ISIS recruited into the Cubs of the Caliphate, many to go as suicide bombers, she feared her son would suffer a similar fate. She also became pregnant.

Desperate to escape, Passoni took her son in a taxi and headed for the border of ISIS territory, but the fearful driver turned her over to the ISIS police instead. Passoni’s husband agreed to vouch for her, and she was confined under house arrest with ISIS cadres guarding her when he was absent, preventing her from making another attempted escape.

Eventually, Passoni managed to convince her husband to join her in an effort to flee, and with the help of smugglers the little family of three found its way back to Belgium.

If they had been caught, here husband most likely would have been beheaded, and would have been returned to Raqqa, then forced into marriage with another fighter. Other women who have tried to escape have been raped and in some cases murdered by smuggles, according to the accounts of eye witnesses in our ISIS Defectors Interview Project.

Passoni’s husband is now serving prison time in Belgium while she has been released conditionally. Her children, who were temporarily removed from her custody when she returned to Belgium, are now back in her care.

She spends her free time lecturing to young Belgians about the dangers of joining ISIS. A video clip of interview with the International Center for the Study of Violent Extremism (ICSVE) can be found here.

Passoni’s story follows patterns similar to those of many women who join ISIS. The path to violence almost always involves the classic interaction of four important factors: a group, its ideology, social support, and personal motivations and vulnerabilities. But there are also, commonly, more specific reasons.

One is political outrage. Many Muslim women as well as men around the globe witnessed the whole of Syria collapse into anarchy and violence under Bashar al Assad. They grew furious watching Assad’s scorched earth policy towards not only opposing combatants but also against Syrian civilians. That these atrocities continue to this day and often are just as brutal as what ISIS does to local populations that defy its rule is not lost on potential recruits. The motivation for some women who joined early in the conflict, as with their male counterparts, was rooted in grave concern about Assad’s sheer brutality in Syria, and in response to the political impasse in the country.

Others were already incited by ISIS’, and before that al-Qaeda’s, narrative that Islam, Muslim people, and Muslim lands are under attack by Western powers and that a defensive jihad is necessary.

These women were lured by graphic YouTube videos of real suffering and injustices perpetrated against Muslims worldwide under dictators propped up by Western powers. The psychological impact of images of wars prosecuted by Westerners combined with civilian casualties may have played an important role in their decision to try to help defend the weak.

In fact, in studies of moral judgment, women and girls often make their assessments more relationally than men, and may judge what might normally be defined as an immoral act to be moral if it saves a life, particularly the life of someone to whom a woman is related to.

ISIS and al Qaeda have been successful at garnering loyalties in support of a transnational ummah (Muslim community) and building up the idea of a greater family (fictive kin, in the jargon of social science) through the formation of the so-called Islamic Caliphate. They have been successful tapping into various dimensions of populism and promote a doctrine that not only attempts to play on Muslim sentiments worldwide but also unifies Muslim demands against a common enemy—the West.

Add to the mix the complex discourse on marginalization and discrimination of Muslim women in the West. Women in Europe who want to wear headscarves or niqab (full-face covering), or a burkini for that matter, may find themselves on the wrong side of the law in some countries. They also may be sidelined in the workplace or passed over for jobs. Some may be harassed on the streets.

Recruiters who are promising female empowerment and emancipation, both political and economic, can be very persuasive to women who are feeling disillusioned and distressed by living in the West. They are told of a utopian state where all Muslims are included and where being a Muslim is an advantage versus a disadvantage; where personal dignity, honor, purpose, significance, and the material benefits of free housing, job training, free health care, matchmaking and salaries are promised to all who join.

For many women who join ISIS, the geographical relocation to Syria and Iraq serves as an attractive escape from personal and emotional problems—for example an overbearing, violent, and drunk father or husband—or the inability to attract a man considered a proper mate.

Until very recently, when it started losing significant swaths of territories in Iraq and Syria, ISIS claimed to embody the actualization of Islamic ideals. Women were invited to join in hopes they could win forgiveness for their sins and and thus attain paradise when they pass into the next life.

According to the caliphate’s preaching, any man or woman who has seriously “sinned” could redeem him or herself by joining the Islamic State and, best of all, by volunteering for a suicide mission. There is nothing like “martyrdom” to guarantee to the person who comes to believe in it an immediate place in paradise.

Women are often believed to be coerced, or even forced, into following their men into Islamic State. In some cases, fears of abandonment, loyalty, and coercion do play a role.

Such is the case of a European we’ll call Laila. When her fiancé first flew to Istanbul to join the Islamic State, she turned him in to police. Laila thought she had saved him from going to ISIS, only to find out after her marriage that he had not given up his dream.

Laila’s husband presented her with the difficult choice of divorce if she refused to let him join ISIS, or, as he told her, “being a good Muslim wife who supports and follows the lead of her husband.” Hoping that it would be all he believed it could be, she followed him.

Laila’s husband was killed, leaving her pregnant and fearing she would be forced, like other ISIS widows, to marry another fighter. Laila’s father courageously struggled to hire a series of smugglers to get her out before her baby was born inside the Islamic State, and she agreed. But as she began her perilous road to freedom, ISIS, realizing she was on the run, messaged her parents demanding that she return to the group to first bear her child and nurse it, for, as they texted, “The baby is ours.” She eventually made it out with the child.

Laila, fortunately, did not face the fate of many women who are smuggled alone back to safety—rape and coercion by criminals.

According to the statistics ICSVE researchers have been able to compile, foreign women who join ISIS return at a much lower rate than men. It is unlikely that’s because they want to remain with the group. It probably reflects the fact that it is difficult for a woman to escape ISIS with no money of her own, living constantly under the control of men, going outside the house only with difficulty, then facing the depredations of smugglers once they are on their way.

Women who have borne children inside ISIS territory have encountered difficulties escaping with their children, who lack officially recognized identity documents. A Belgian ISIS mother, for instance, contacted her consulate in Turkey before attempting to escape ISIS territory, only to be told that her husband, the father of her babies, would also need to be present to apply for and receive papers for her children. She decided to stay put rather than attempt escape with no certainty of ensuring her children’s eventual documentation according to interviews we conducted in Belgium last year.

ISIS has managed to attract both adults and teen girls. Schoolgirls from London to Scotland to the Netherlands to Kyrgyzstan have run away to ISIS. Some were enamored of adventure and excited by men who lured them with promises of romance.

Turning to the blog posts of ISIS internet recruiters such as Umm Laith and Bird of Janna [Paradis], they likely believed they were embarking on a romantic and heroic venture to better the world and find unconditional love, trust, and loyalty. Promises of an Islamic life, riches, and torrid love affairs are common fare among male and female Internet recruiters.

French journalist Anna Erelle, posing as a younger vulnerable teen, was contacted by a French fighter the same day she posted his video on her fake Facebook profile. Internet relationships can easily provide frequent contact and convey caring and real intimacy. Her recruiter dogged her constantly, Skyping, texting and talking with her multiple times a day. To a lonely and confused young woman, this can be an intoxicating amount of attention. Internet recruiters often talk to them more than their own family members, honing in on vulnerabilities and needs.

Many who joined ISIS, women included, believed that the ISIS “Caliphate” would deliver a “pure” Islamic lifestyle and that it would operate by “pure” Islamic ideals, despite the bloodshed and brutality that have become a defining characteristic of the group.

In fact, ISIS uses cruelty to communicate fearlessness, and coupled with battlefield successes, in 2014 and 2015 it managed to attract thousands of fighters from all over the world, including hundreds of women, to what it portrayed as a triumphant cause.

Part of its strength lies in its ability to demonize the opponents and avoid the moral conflict that comes with killing and engaging in acts of brutality. When women question this gruesome spectacle, the ISIS responses is that, “All revolutions require bloodshed, but ultimately those who fight for the cause will live by pure Islam.”

In fact, ISIS recruiters operate much like cult recruiters, meeting needs in the first interactions and then gradually drawing their victims deeper into the group—to a point where the group no longer caters to them but instead takes over their lives.

As the New York Times reported in 2015, a young woman in Washington State, whose alcoholic mother had left her in the care of her grandparents, tweeted out the question of why ISIS would behead a journalist. She received an answer—from ISIS recruiters—who told her that all revolutions are characterized by bloodshed and that this [ISIS struggle] was no different. They then began to seduce her into the movement by lavishing attention and gifts upon her.

Similarly, a teen girl in London followed ISIS profiles on Twitter, only to find that they followed her back, suddenly making her “popular” with many followers, and they messaged her about joining the Islamic State. They told her that, as a Muslim, she should make hijrah—that is, travel to live in Islamic lands rather than live sinfully in the kafr (unbelieving) U.K. When she protested that she was too young to marry one of the “brothers,” she was told she could come and marry after a year or so. When her case came to the attention of authorities, she admitted that from the pictures she was being sent of ISIS housing in Syria, she thought she would be traveling to “Islamic Disneyland.”

Converts to Islam are especially vulnerable to ISIS recruitment, as they often have limited knowledge of religion. They often want to prove themselves, sometimes by expressing loyalty through violence. At the same time, they may be alienated from family members, which leaves them vulnerable to others who begin to fill that gap.

American teen Shannon Conley fell into this category. She converted from Catholicism to Islam at age 17 and then tried to join ISIS at age 19. She found her interpretations of Islam on the internet and was convinced by violent extremists that Islam is under attack and that the West is the enemy of Islam. Interviewed by the FBI when she came to their attention, Shannon admitted to downloading instructions on how to carry out a VIP attack inside the United States and that she had come to believe that military bases, and even civilians who frequent them, could be legitimate targets of attacks.

She also Skyped and fell in love with a Tunisian ISIS fighter who convinced her to become a hero by leaving her job cleaning bedpans, marrying him, and working as a medic for ISIS. Shannon attempted to travel to Syria and was sadly disappointed when she was arrested on the tarmac trying to board a plane out of Denver, Colorado. She is now held in a maximum-security prison.

Girls who go to join Islamic State often leave confused schoolmates and BFFs behind. Two young Bosnians who had grown up in Vienna continued to contact at least one of their friends via social media, likely inviting her to follow. A young girl in a London school appears to have influenced three of her schoolmates to follow her into the Islamic State.

Contagion effects are normal among young people, particularly teen girls, and have been observed in relation to suicide to psychosomatic health epidemics. This is to be expected and should be guarded against in relation to terrorist recruitment as well.

Women who join ISIS are joining a misogynist organization, but it is important to note that they also are empowered in multiple ways by the group. Foreign women who join are invited to serve in the ISIS hisbah (morality police). They are tasked with enforcing dress codes and the strict ISIS interpretations of sharia law.

These women are armed, operate above the status of ordinary civilians, and answer to practically no one—enjoying an elevated status they may not have found back home.

Women who earn poorly back home might also enjoy a beautiful home taken from the enemies of ISIS or a captive forced into slavery who does cooking and housework, in some cases looking after the husband’s sexual desires. Even among women, the ISIS true believer is taught to dehumanize these captive women and legitimize their enslavement.

If they are not in the hisbah, young foreign women are invited to join a group of women operating out of Raqqa that draw other women, as well as men, into the group. Females seducing men into the group are powerful indeed. American ISIS recruit Mohamad Jamal Khweis appears to have joined precisely for this female promise of marriage, having left the U.S. on a purported vacation but flown in a circuitous route to Istanbul. He later claimed to have met a woman whom he immediately married and with whom he traveled to Iraq to join the group.

Contrary to some assumptions, females who get to the Islamic State are not gang-raped by ISIS men. But they are expected to have husbands and, indeed, ISIS runs a marriage bureau specifically for that purpose. Women who marry into ISIS are indoctrinated into believing in the spiritual benefits of their husband’s “martyrdom,” with some even welcoming their enhanced status as a “martyr’s” widow as a positive benefit. Moreover, widowhood benefits are promised to ISIS wives in the event their husbands are killed.

According to ISIS defectors we interviewed, in reality, these are rarely paid with any consistency. On the contrary, ISIS widows found themselves handed off to their husband’s friends or put into dire living situations until they agreed to marry again—some marrying as many as thirteen times in succession. One female ISIS defector with a baby in arms told us she escaped the group because she did not want to be forced to marry a fourth time after her third husband was killed.

Most countries accept their female returnees from Iraq and Syria and many countries do not prosecute these women—or if they do, they receive lighter sentences. This is due to the notion that they only followed their men as a result of being tricked or coerced, which often is not the case.

In the Balkans and Central Asia, we were told by intelligence and law enforcement that women are “zombies” (following their men and controlled by their men). But our research shows that ISIS women often followed their men willingly into Syria and Iraq, and in some cases willingly joined them in homegrown terrorist attacks.

Some may have agreed to go out of fears of abandonment and financial ruin, yet others were instigators. In Kyrgyzstan, for instance, two older women talked their extended families into traveling to Syria to join ISIS, believing that they would better their financial lot and be able to live by what they believed to be “true” Islamic ideals. When disillusionment set in, one of these grandmothers was able to smuggle her grandson back home who, according to her close associates interviewed in Kyrgyzstan, brought a message from the rest of the family: “He’s the only one we could get out, we are hopelessly lost.”

Contrary to some societal assumptions that downplay the role of women as perpetrators of violence, women in ISIS frequently are agents of violence within the group. Former members of hisbah told us themselves about flogging and biting other women with metal teeth as punishments. Similarly, reports from those on the ground in Syria state that women inside ISIS have been trained to throw grenades, use weapons, and have been indoctrinated for “martyrdom” missions.

Indeed, the marriage certificate for ISIS wives was changed in recent years to state that a woman does not have to seek her husband’s permission to become a “martyr.” She only needs the permission of the ISIS “caliph,” Abu Bakr al Baghdadi.

Following in the paths of many conservative terrorist groups that do not encourage female fighter roles, ISIS is no different in pushing them into suicide missions when cornered, facts born out in the recent battle for Mosul.

Given that not all ISIS females were forced to join the group, nor lacking in agency with regards to the roles they played in it, we need to be cautious with both female and male returnees from the Islamic State.

While women who join ISIS are often portrayed as “brainwashed” by men, cultural biases that overlook the role of women as willing participants, including narratives that deny the role of political grievances that drive women to join ISIS, may be dangerous.

ISIS has relied on women for logistical, propaganda, recruitment, and policing work. During the final battles for the recapture of Mosul, ISIS sent numerous females to blow themselves up in attacks on encroaching soldiers.

Independent of gender, anyone who joined the Islamic State group likely had some psychological and social issues before leaving that made them vulnerable to recruitment, and once in, they often also have been weaponized and indoctrinated into a vicious ideology.

Men who went through sharia training told us of having to behead a prisoner before giving their bayat [pledge of allegiance] to the terrorist group while women in the hisbah told us of being turned into sadistic torturers. While women are less often weaponized, there is increasing evidence of weapons training for female cadres in the last year.

As ISIS increasingly calls for homegrown attacks in the West, it is unclear if they will reach back to females who have returned home. For instance, one wife of an ISIS fighter in Kosovo was not prosecuted for joining and traveling to a terrorist group, while her husband was. He serves a four-and-a-half-year sentence and still avows loyalty to ISIS while his wife lives freely in society, although under police surveillance. She is known to continue internet contacts with the group as well as communicate with her husband who expressed willingness to return to the group if released.

There are ample other examples of returned foreign fighters from ISIS and other terrorist groups where the returnee continued on at home as a “sleeper” and reactivated over time. The possibility that ISIS women would do the same is a factor we cannot afford to ignore.

In our experience, ISIS has contacted members who defected, insisting that they continue to serve the group even when they wish to sever ties. Similarly, returnees who may have had difficulties that led to their wish to travel to Syria and Iraq to join, are likely to face these same difficulties, if not worse stressors, upon their return. They have also witnessed extreme brutality that may leave them in a traumatized state.

Interviews in the past with traumatized Palestinians often revealed how easy it was to volunteer for a suicide mission if one already was psychologically numb as a result of post-traumatic stress disorder (PTSD).

As one interviewee said, “It’s a small step to take if we are already dead.”

Indeed, “martyrdom” ideology serves as a kind of psychological first aid when applied to people suffering PTSD. The individuals gain immediate relief from painful flashbacks and post-traumatic arousal states by escaping into a death they believe is simply a doorway to paradise and glory, and may even experience states of euphoria in contemplating taking their own life in this manner.

These same post traumatic vulnerabilities may be operating for ISIS female returnees who, in many cases are not prosecuted nor mandated into any kind of treatment, despite likely suffering stigma, personal and psycho-social problems, and difficulties reintegrating.

Public sympathies for ISIS female returnees, who are often handed down shorter sentences or pardoned, may only complicate the prospect of effectively dealing with female returnees who need special care and attention. It is our view that anyone who joins a terrorist group like ISIS, by virtue of the likelihood that they are traumatized by what they experienced and may also be ideologically indoctrinated or weapons trained, should first be prosecuted and, if judged amenable to it, be allowed to receive a lightened prison sentence, or sidestep prison time altogether by voluntarily committing to engage in a psychological program.

A well carried out rehabilitation program can help them to understand and address the personal reasons that resonated with ISIS calls to recruitment and their violent actions, as well as be moved to find other solutions to either their psycho-social problems and/or concerns about their grievances.

Some ISIS returnees may not voluntarily take part in rehabilitation. Others may only pretend to cooperate. That said, if carried out well and with careful assessments along the way, many can be rehabilitated and reintegrated into society in a psychological state that makes it less likely that they would again be manipulated or once again answer the call to terrorism.

While we are preparing for the return of female foreign fighters, we also need to educate youth, including female youth, regarding the truth about ISIS and their virulent online and face-to-face recruitment. Despite rapidly losing its territory, ISIS has already produced innumerable propaganda materials that are likely to continue to circulate on the internet. The digital “Caliphate” will likely continue to recruit.

Initiatives like our Breaking the ISIS Brand Counter Narrative Project using insiders to denounce the group will continue to be useful to interfere with and disrupt ISIS recruitment. Through a combination of education, prevention, and direct intervention measures, we can ensure the safety of our citizens while ISIS tries to reconstitute itself in the face of territorial loss and the eventual return home of most of its foreign fighters.