In May, a U.S. special operations mission in Syria killed one of the top money men for ISIS, Abu Sayyaf, and captured his wife Umm Sayyaf. It would have been great to take Abu Sayyaf alive, but it was known at the time that his wife was also a high-value target, and subsequent interrogations have proven her to be a major asset. In fact, Nancy Youssef at the Daily Beast judges Umm Sayyaf to be “the richest human intelligence source to fall into U.S. hands to date.”

Umm was not a bystander to the nightmarish evil of the Islamic State—she was an active participant, a “principal adviser” with “a lot of details” in the words of one U.S. defense official. She helped manage the ISIS women’s network, including their vast sex-slave operations.

It has long been clear that the terror state is keenly interested in recruiting women, and they have been remarkably successful, considering that even the most naive young recruit knows a life of second-class status in the barbaric ISIS patriarchy awaits them. It is not considered polite to dwell on how so many young women living in the Western world were conditioned to believe such a life is proper and desirable.

Some of them change their minds once they get a close-up look at daily life in the Islamic State. The UK Daily Mail relates the testimony of a 23-year-old Syrian woman who defected from ISIS after holding a “senior role” in the women’s network and now seeks to warn potential recruits of what awaits them. “The caliphate is not what you think it is,” she said to ISIS-curious women. “Women are raped, sold, and stoned. Corpses are on display publicly for weeks.” She spoke of collecting batches of European girls at the Turkish border and delivering them to the Islamic State capital of Raqqa for indoctrination and marriage.

Umm Sayyaf, who was much higher up in the ISIS women’s command structure than the Syrian defector, has provided her interrogators with details about how the structured and brutal women’s network within ISIS functions as a parallel, inferior system under the command of the male-dominated government and military machine. According to Umm Sayyaf, ISIS is dependent on its women to “keep and retain fighters and run the state.”

The Daily Beast reports:

On the lower rungs of ISIS, women are tasked primarily with serving the sexual needs of ISIS’s male members, maintaining a home and producing future ISIS fighters, U.S. officials and counterterrorism experts said. In addition, in the territories that ISIS controls, there are women who work for the religious police, or Al-Khanssaa Brigade, ensuring other women are abiding by ISIS’s strict religious and social standards. Often they are Arab women who can tell others when they are not abiding by the rules. There are female spies there to make sure other women stay in line. And still others facilitate a sex slave trade, assessing other women or arranging temporary marriages for them.

Women are promised as brides to male ISIS recruits—brides who have been trained at a hostel to serve a proper submissive role. “Men who seek to live in strict jihadist interpretation of Islam also enjoy the promise of a wife whose life will mainly be at home,” the Daily Beast notes. Multiple brides are sometimes promised to a single male recruit, although analysts believe there is actually a severe imbalance of 10 men to every woman inside ISIS, making those promises difficult to keep, even when outright slavery is employed.

It’s worth recalling that a Yazidi slave was freed in the same operation that killed Abu Sayyaf and captured his wife.

Women also figure prominently in the Islamic State’s online recruiting effort, with some 500 of them working on Twitter. The one thing they’re apparently not permitted to do is actively participate in jihadi military operations, which is apparently disappointing to some of them. The Daily Beast observes that ISIS’s godfathers in al-Qaeda employ female suicide bombers, as do terrorist allies such as al-Shabaab in Somalia and Boko Haram in Nigeria. In fact, several of the suicide bombers employed in the horrific wave of violence perpetrated by Boko Haram in Nigeria over the Fourth of July weekend were reportedly women.

Perhaps Umm Sayyaf’s intel about ISIS’s dependence on women will provide a method of attacking their far-too-successful recruiting machine. If many of the male recruits are lured with promises of brides and sex slaves, advertising the short supply of women in the Islamic State could be a good way to combat its sales pitch.

Teaching vulnerable women in the West about what truly awaits them in the “caliphate,” using information gleaned from Umm Sayyaf and female defectors, could be an effective counter to the aggressive ISIS presence on social media. It seems clear that we know much more about the inner workings of ISIS thanks to that special-operations raid in May, which may be remembered as one of the most consequential operations of the war.