When the so-called Islamic State (ISIS) encouraged women to join its newly founded “caliphate,” thousands of women from Europe, North Africa, the Middle East, and beyond answered the call and moved to ISIS-controlled territory. In line with the group’s extremely gender-conservative ideology, at first the assigned roles of female members of ISIS were mostly associated with marriage and raising children. This started to slowly change from 2015 onward, when the group came increasingly under pressure by the international coalition established against it, and culminated during the battle for Mosul in June/July 2017 when dozens of women conducted suicide attacks. This shift in roles highlights that external security pressures can lead even terrorist organizations with an extremely gender-restrictive ideology to include women in combat roles.

Even compared with other contemporary violent Islamist groups, ISIS is particularly gender-conservative. While most armed Islamist organizations ascribe to relatively strict gender norms, this has not stopped women getting involved in political and military roles in several of these, such as Hamas and Hezbollah. In some cases, women were included because they shaped space for themselves, in others because the organizations recognized the tactical value provided by female operatives. Even though ISIS actively addressed women in its propaganda and recruitment strategies, their role was largely to be of domestic nature. The group enforced strict gender segregation in the territory under its control. Women were required to follow the group’s rules on what was considered acceptable clothing and interaction with non-mahram men. Women’s mobility outside the house was highly restricted. Exceptions included a limited number of women who worked in medical or educational roles, which is necessary in a strictly gender-segregated society that does not want to completely abandon women’s healthcare and education.

There is some evidence that especially some of the European women who joined ISIS in Syria were interested in expanding their roles and participating in combat. For example, in 2015, a group of women close to the female-only policing unit Al-Khansa Brigade, which was established in the de facto ISIS capital Raqqa in Syria, released a document on the roles of women in the group. They referred to the history of women’s participation in other conflicts, such as in Chechnya and Iraq, and stressed that women could be included in combat if the security situation required it. While not involved in combat, the female members of the Al-Khansa Brigade were nevertheless involved in perpetrating violence in the name of ISIS. Accounts from Raqqa report the torture and killing of women and girls who were found not to abide by rules on women’s clothing or behavior in public.

First unverified reports of women being present on the frontlines in Syria date as far back as July 2014. There have been unconfirmed reports of ISIS training female suicide bombers since early 2015. In February 2016, according to newspaper reports, seven female members were placed in custody, and three killed, following an attempted suicide attack by a woman in Libya. Shortly afterward, unconfirmed reports claimed that women had participated in an attack on Ben Gardane in Tunisia in early March 2016. Another female suicide bomber was reportedly deployed in Libya in August 2016. In the context of ongoing conflict, it is hard to establish if these attacks did indeed involve female fighters and not men disguised as women, a tactic adopted by some non-state armed organizations. It is possible that the women acted on their own initiative, maybe with support by single members of the organization, but without the leadership’s approval. Nevertheless, a number of planned attacks by female-only terrorist cells in France and Morocco in autumn 2016, which were encouraged and guided by ISIS members over the internet, seem to indicate that at least some male operatives were not entirely opposed to the involvement of female fighters.

This gradual shift of women’s engagement from supportive roles to participation in combat culminated during the battle for Mosul in Iraq. Whereas so far, women’s involvement in combat had been punctual, in the last days of the battle for Mosul, when ISIS faced extreme pressure from Iraqi troops and its allies, a series of suicide attacks were conducted by women. Media reports quoting Iraqi security officials speak of 38 attacks that were conducted by early July. Little is known about the women, and their backgrounds and motivations. It cannot be excluded that, at least in some cases, coercion played a role, as it did in some of the suicide attacks by female bombers associated with ISIS’s predecessor Al-Qaeda in Iraq in the 2000s. Unlike other high-profile attacks, the operations by the women in Mosul were not claimed by ISIS on any of the channels usually used by the group. While this could be read as an indicator that the suicide attacks were not, in fact, directed by the group, the absence of official claims could also be a tactical move by the organization. Societal attitudes are often hostile to the involvement of women in combat. Other armed organizations, such as the Taliban in Afghanistan, have had to readjust their official position on female participation in combat out of fear of societal backlash.

The fact that the definitive shift in women’s participation from supportive to military roles took place during the battle of Mosul, when ISIS was facing extreme security pressures, supports claims made in existing conflict and terrorism literature, according to which even highly gender-conservative terrorist organizations resort to the inclusion of female fighters if the security context warrants it. The evolving roles of women in ISIS should serve as a reminder to practitioners and policymakers working on women and violent extremism that, even in the most gender-restrictive groups, ideology is rarely a barrier to female participation in combat that cannot mitigated or overcome by the organization if deemed of tactical advantage to their aims.

Jennifer Philippa Eggert is a Doctoral Research Fellow at the University of Warwick. @j_p_eggert