( CNN ) There is a special kind of hell reserved for the women who fall into the clutches of today 's Jihadi fighters . We are all familiar with the brutality of ISIS , the self-anointed Islamic State , or Boko Haram , the Nigerian terrorists who have pledged allegiance to ISIS . This new wave of violent Islamist groups proudly brandishes medieval methods of cruelty through modern technology as a tool of recruitment and intimidation . But there is something very different about the way they treat women . The jihadi chiefs have a strategy beyond the battlefield . Their treatment of their female victims plays an important part in their ambitious radical strategy . Killing the enemy , the men , is a tactic for winning battles and conquering territory . What they do to women has an altogether different purpose : It is part of the larger plan of building a `` caliphate , '' a Sharia-ruled state complete with controls and norms harking back to the seventh century or , rather , to the group 's interpretation of life in the early days of Islam . Yazidi girls who slipped ISIS after its siege of Mount Sinjar describe how they were sent to slave warehouses along with hundreds of other women . There , they were lined up in groups of 50 and displayed for ISIS fighters to choose among them , some for marriage , others for sexual slavery . The stories told to journalists or to human rights workers are confirmed by doctors who have examined the girls and say they have found evidence of repeated sexual assault . An investigation by Human Rights Watch found `` a system of organized rape and sexual assault , sexual slavery , and forced marriage by ISIS forces , '' actions that the group says `` are war crimes and may be crimes against humanity . '' In Nigeria , Boko Haram also has a very specific approach to women . The 276 students kidnapped one year ago make up a small portion of the 2,000 women and girls kidnapped by the group since 2014 , according to Amnesty International . There , too , women captives move from house to house and village to village , forced to convert when they are not Muslim , and prepare for marriage to jihadis . It 's a stark change from the previous generation of jihadis , when Osama bin Laden headed al Qaeda . Women were not a big part of al Qaeda 's immediate plans because al Qaeda , unlike ISIS , viewed the establishment of a caliphate as a distant goal , one for future generations . In contrast , ISIS is actively engaged in building those social structures . And if you want to build a new society , you need more than soldiers . You also need women . Women are indispensable for establishing a functioning community , even one whose laws are brutally repressive . Even if women are viewed as the property of men , they are still needed , not just for cooking , cleaning and sex , but to keep the home and raise children ; hence the methodical capture , assault and subjugation . It is no accident that Boko Haram has targeted students , as it did in Chibok , or that Somalia 's Al-Shabaab Islamists killed scores of women in the massacre at Kenya 's Garissa University in Kenya . As in previous conflicts , women are spoils of war and rape is a weapon of war . It is a way to humiliate the enemy , a `` reward '' for soldiers and a tactic of ethnic cleansing . During the Bosnian war of the 1990s , experts said Serbian soldiers engaged in systematic rape , thinking the babies of raped Bosnian Muslim women would be Serbian . In Darfur , government-backed militias were accused of using mass rape to humiliate the non-Arab groups . But this is different . The women are not simply abused and discarded . ISIS and Boko Haram are enslaving them and incorporating them into the daily life of territories they rule , subjecting them to asphyxiating restrictions and abuses that have caused many of them to attempt suicide , according to some of those who escaped -- a phenomenon reminiscent of Afghanistan during the rule of the Taliban , another radical Islamic group that managed to take control and impose unspeakable rules for women . ISIS is going to great lengths to prove how its treatment of women , including the selling of Yazidi prisoners as slaves , is in keeping with Islamic law . Its online magazine cites Islamic writings proclaiming : `` We will conquer your Rome , break your crosses , and enslave your women , by the permission of Allah . '' The worst fate is reserved for non-Muslims , such as Yazidis , but Muslim women in areas seized by Islamists have seen disaster . From Mosul , Iraq 's second-largest city , a modern town until ISIS conquered it last year , women say , `` They have withheld all freedoms from us '' and describe oppressive , fear-filled lives . The brutality of the new jihadis is more than mere sadism . If it is madness , it is madness with a method . And when it comes to women , the method is one that aims to control them as a way to establish the society they envision , one where some women say life is simply not worth living .
Frida Ghitis : ISIS and other jihadi groups see women as crucial in role of caliphate they want to create . She says the groups want to enslave women , tie them to a long outdated view of how society should work .