ISIS territory, from everything we hear, is an absolutely miserable place to live. This should be a liability for ISIS: if it's really so terrible to be live under its rule, you'd think that a number of their fighters would want to leave.

There haven't been waves of mass defections from ISIS — partly because, according to some reports, ISIS commanders shoot people who try to leave. But a few people have left the group. Scholars Anne Speckhard and Ahmet S. Yayla found some of them and got them to agree to interviews, excerpts of which they have published in the newest issue of the journal Perspectives on Terrorism.

The defectors' stories are harrowing. They're also a valuable window into how life in ISIS works — and some of the group's real weaknesses.

Why the defectors quit: life in ISIS territory is awful

Speckhard and Yayla found these defectors, all of them originally from Syria, on the Turkish-Syrian border. To a man, they had horrific stories to tell. Take, for instance, this account from one of the defectors (names were withheld or replaced with pseudonyms) about how ISIS executed prisoners where he was stationed:

There is a well by the name of Hute. There they cover the eyes of the prisoners and tell them, ‘You are free now, just walk now, but don’t open your eyes.’ They walk and fall into the well. It smells horrible because of all the corpses inside the well. I know that over three hundred people were thrown into that well.

According to Speckhard and Yayla's sources, such cruelty is central to ISIS's strategy. The group uses fear of atrocity to keep the population in line, and to intimidate other armed groups. One fighter recalls how ISIS used child suicide bombers to drive the Free Syrian Army (Jaysh al-Hur in Arabic) out of the city of Raqqa roughly two years ago (note: Daesh is another name for ISIS):

When Daesh came to Raqqa, Jaysh al-Hur was in power, but Daesh took over for many reasons. First, Daesh sent small groups to establish themselves inside the city. Secondly, they sent suicide bombers of young boys, especially to the gates where Jaysh al-Hur had guards. This was very effective, as everyone feared the suicide bombers and it was very difficult to distinguish if an approaching child was a suicide bomber or not. Being unwilling to shoot a possibly innocent child, the sentries would run away and Daesh could enter.

Some defectors say they were driven away by this cruelty. "What I don’t like [is] if someone did something wrong [then] they tried to waterboard him," a defector who calls himself Abu Shujaa said. "What I don’t like is that if they don’t like someone they just behead him. Or if a woman is not wearing hijab they bring someone to flog her, or if someone doesn’t believe they cut his ear."

The Syrians interviewed by Speckhard and Yayla say they were particularly stunned by the gap between what ISIS claimed it would be and the way it actually worked.

"In 2014, I realized that Daesh were liars," another defector, Abu Walid, said. "For instance, there was an [ISIS] guy who raped a woman, but got away with it."

According to the defectors, the reality of life in ISIS territory stymied the group's recruiting in Syria. While people had previously joined out of a sense that ISIS's cause was just and that the group could provide them a better life, this fantasy has been shattered by the grinding poverty and misery that characterizes life under ISIS.

As a result, the interviewed defectors say, recruiting has declined. We can't know that this is true for sure, given that this is testimony from only a few Syrians and we lack hard data, but it is significant that former ISIS fighters have a feeling that recruiting is tapering off.

"The few people who join now do so only because they need to eat. They are the ones who don’t have work," Abu Walid said. "The rest try to escape to Turkey or Lebanon, or go by sea."

What these interviews tell us about how ISIS works, and doesn't

There are limits to Speckhard and Yayla's research: Their sample is small, for example, and limited to Syrians. But the testimony is consistent with other research about ISIS defectors, as well as broader testimonies that suggest ISIS is just plain bad at building a government that has real popular support among the people it rules.

Earlier this year, the International Centre for the Study of Radicalisation put together a report analyzing testimony from 58 ISIS defectors. These defectors included ISIS recruits who'd joined from all over the world, not just from Syria, so the report gave a broader view of the reasons ISIS fighters choose to leave — all of which were consistent with the testimony Speckhard and Yayla gathered.

When I interviewed ICSR director Peter Neumann in September, he explained that there were four main reasons he'd found for why ISIS fighters quit:

Recruits joined to fight Bashar al-Assad, but ended up largely fighting other Syrian rebels, and were disappointed by this. Defectors believed ISIS was too brutal to fellow Sunni Muslims. Defectors said ISIS leaders were corrupt and played favorites. Many also said living conditions in ISIS territory were awful; they'd been promised a glorious caliphate but found squalor.

These grievances are in line with the ones Speckhard and Yayla found: that ISIS is too cruel and doesn't live up to the religious paradise it promises in its propaganda.

Interestingly, Neumann's research also suggested the pace of defections was growing, seeming to corroborate the defectors' testimony that ISIS is facing growing recruitment and retention problems.

"What we can say for sure, based on our data, is that the numbers [of defections] are increasing," he explained. "Two-thirds of all of the public defections happened this year; one-third alone happened in the last three months."

Again, these sample sizes are limited, so it's worth taking the information with a grain of salt. Moreover, defections are still limited, so it's hardly crippling the group.

But the two studies of defectors do help us understand why ISIS's failures as a state are such an acute vulnerability. According to Brookings fellow Megan Stewart, recent insurgencies that have successfully transitioned to being actual states tend to prioritize serving the needs of their population. These groups "invest deeply and extensively in governance activities," she writes, "recognizing them as a critical source of legitimacy."

ISIS isn't doing that very well, it seems. This is especially difficult for ISIS, per Stewart, because the group is losing territory.

"As military pressure against IS intensifies, its governance will likely to get worse," Stewart writes. "However, this poor and restrictive governance enfeebles IS, and as Eli Berman and Jake Shapiro have argued, it could even serve to be the Islamic State’s undoing."

So while defections are not, on their own, a major threat to ISIS, they point to something that is indeed a serious problem for the group — one it's not clear ISIS knows how to fix.