Editor's note: Frida Ghitis is a world affairs columnist for The Miami Herald and World Politics Review. A former CNN producer and correspondent, she is the author of "The End of Revolution: A Changing World in the Age of Live Television." Follow her on Twitter @FridaGhitis. The opinions expressed in this commentary are solely those of the author.
(CNN) -- Just when you thought it was impossible for ISIS to become any more contemptible, the group in a recent publication boasted of its success in bringing the return of slavery. More specifically, it announced and provided elaborate justification for the enslavement of women.
We didn't need a new propaganda effort from the self-appointed Islamic State to know the nightmare that has befallen women in territories captured by its fighters. Now we've had a look at the twisted logic that rationalizes sexual exploitation, killing and enslavement of women and young girls.
Is it any wonder then that women in Iraq and Syria have moved to the forefront of the war against ISIS? They have taken up arms, organized civil protests and warned the world about the threat that ISIS poses.
A woman is leading Kurdish forces fighting ISIS in the city of Kobani, Syria. And a substantial number -- more than one third -- of the Kurdish battlefield troops in Syria are women.
One reason they fight is that women have more to lose than anyone else.
For a time, the rumors seemed so extreme, so outlandish, that they were met with a dose of skepticism: Talk of slave markets, mass kidnappings, women treated as spoils of war distributed among the victorious fighters, sounded like tales from a historic account, not of a 21st-century conflict.
But in 2014, using the Internet, ISIS described what it did with members of Iraq's Yazidi minority: "After capture, the Yazidi women and children were then divided according to Sharia amongst the fighters of the Islamic State. ..." The explanation included "scholarly analysis" to justify the religious logic and social benefits of reviving the slavery of women. "One should remember that enslaving the families of the kuffar -- the infidels -- and taking their women as concubines is a firmly established aspect of the Sharia, or Islamic law."
It seems pointless to discuss religious doctrine with a group determined to kill its way into the imposition of seventh-century norms more than 1,400 years after they were written. A number of top Muslim clerics have rejected ISIS' interpretation of Islamic law. And some Muslims argue the Quran is actually egalitarian.
ISIS, in contrast, finds slavery and the holding of concubines a beneficial practice, writing that "a number of contemporary scholars" say the end of slavery has led to an increase in "adultery, fornication, etc."
The latest publication confirms what human rights investigators and survivors of ISIS have reported. The United Nations says slave markets now operate in Raqqa, the ISIS "capital" in Syria, and in Mosul, until recently a modern city in Iraq.
U.N. investigators interviewed witnesses, who told of women taken captive by ISIS, sexually abused and handed to slave traders. The United Nations estimates there are at least 2,500 victims. Others say the number may be much higher.
When Kurdish forces recaptured Mosul Dam, they reportedly said they found a woman naked and tied up, who had been raped repeatedly by ISIS men. Similar reports have come from other ISIS-controlled areas.
Just like the publicized beheading of captives has a strategic purpose, the treatment of women as battlefield loot is a way of enticing new recruits.
But it is also a powerful motivation for women to join the fight.
In the battle over Kobani, just across the border from Turkey, ground troops are led by two top officers of the YPG, the Kurdish People's Protection Units. One of them is a woman, Mayssa Abdo, known in the battlefield as Narin Afrin. About 35% of YPG's forces are women. Then there is YPJ, the Women's Protection Unit, counting 7,500 uniformed fighters, some barely bigger than their rifles. Kurdish women from Turkey have volunteered to fight alongside their Kurdish brethren in Syria.
Inside Mosul, women organized resistance against ISIS' oppressive rule. The women's rights activist Sameera Salih al-Nuaimy denounced ISIS atrocities on social media. She was arrested, tortured and executed by an ISIS firing squad
Women physicians in Mosul organized a strike when ISIS ordered them to cover their faces. At least one of the strikers was executed, as have been countless female lawyers, doctors and other professional women.
A turning point in global attention to the threat posed by ISIS came in August, when a woman, a Yazidi legislator, took the floor in the Iraqi parliament, saying ISIS was committing genocide against Iraq's Yazidis. "Mr. Speaker," cried out Vian Dakhil, the only Yazidi member of parliament, "We are being slaughtered. We are being exterminated."
Since then, while the United States helped save thousands of Yazidis and started bombing ISIS without putting "boots on the ground," countless women, mostly Kurdish, have laced up their boots and headed to the battlefield.
The worst of ISIS treatment is reserved for "infidels," or for those defying their orders. In areas under ISIS control, women are required to observe strict clothing rules and are not allowed to leave the house without a male relative. Violators can be whipped or even executed. It's worth remembering that many of the women facing these restrictions had been living modern lives.
Just when it seemed ISIS could not be more offensive and threatening, it has provided everyone, especially, women even more reasons to fight back.