When I sit down with ISIS members Lukas Glass and Alexander Bekmirzaev, three weeks have passed since their capture by the Syrian Democratic Forces (SDF), stumbling through minefields out of the tiny pocket which is all that’s left of the Islamic State.

VICE sits down with Lukas and Alexander in a military base in the city of Hasekah, part of the Autonomous Administration of North-Eastern Syria – more commonly known as Rojava. Since their historic resistance against an ISIS siege in the city of Kobane back in 2014, the Kurdish People's Protection Units (YPG) and Women's Protection Units (YPJ) forces have joined up with Arab, Christian and Turkmen forces to form the Syrian Democratic Forces (SDF), the armed wing of the democratic, women-led administration.

Backed by airstrikes from a US-led coalition, they’ve spent four gruelling years in house-to-house, village-to-village combat, driving the self-styled Islamic State out of cities like Manbij and Raqqa and reducing their caliphate to less than one percent of its original size. At the time of writing, ISIS fighters numbering in the low thousands were left besieged in a couple of oil-town settlements beside the Iraqi border.

Defeat is written in the surrendered men’s faces. They shuffle into the office in flip-flops, handcuffs and blindfolds, though their restraints are swapped for cups of coffee and we speak freely while their guard smokes outside. Their hair is lank and they’re bony-thin: by this stage, people are eating grass to survive behind ISIS lines. German 23-year-old Lukas’ forehead is pitted with what look like acne scars, where he scraped at his own flesh with a stone to raise a “prayer bump” as proof he’s been praying devoutly.

But when they speak both are smooth and assured. They’ve evidently had time to plot their stories – and to turn vehemently against those around them. Both give a picture of ISIS in disarray, paranoid, infighting, racked by bitter disagreements between local and foreign fighters, torturing and executing people who tried to flee.

Alexander, a 45-year-old Irish citizen originally from Uzbekistan, claims he was possessed by an evil spirit known as a djinn – “similar to schizophrenia” – at the time he chose to travel to Syria to join a rebel group. His story is that he “felt his duty to help Muslims” and started off building a hospital in rebel-held Idlib before ending up in so-called Islamic State when the territory changed hands, “because I’m that kind of person who does unplanned things.” He admits to working as a driver for ISIS, but doesn’t feel he owes anyone any apologies: “Personally, me and my family, I didn’t hurt anyone.”

Lukas is cagey, but more willing to admit responsibility for his actions: “I joined the most dangerous, brutal terrorist organisation in the world. I don’t expect Germany is going to accept me with flowers.” Like Alexander, he denies ever fighting – “I was injured playing football in Germany,” he says. “Even if I wanted to, I couldn’t.” But he concedes he knowingly joined Islamic State, “because I wanted to live in a country where I’m able to practice my religion freely.”

By his account he spent two years with ISIS police, searching cars for drugs and cigarettes, but never meting out punishment more severe than week’s jail. In the end, he says he “saw ISIS was not treating people in an Islamic way” and left the organisation, living as a civilian after being captured during an escape attempt. “I came because I wanted to be free in my religion,” he says. “[But] in Germany I never went to prison for my religion, and in the Islamic State I did.”

Their stories are full of holes. Why would Alexander bring his wife and ten-month-old child to join him on what he claims was a planned three-month trip? Why would Lukas, as he claims, try to live as far from ISIS authorities as possible during the early years of their vast caliphate if it was their rule he craved? But when pushed, Lukas falls sullen and monosyllabic and Alexander retreats to complaints about his own misfortune.

At times, the mask does slip. Asked how life was for his own young wife, Lukas broods for almost a minute. “Terrible,” he says finally, and won’t be drawn further.

Alexander loses his temper talking about the “hypocrisy” of his fellow prisoners who claim to be Muslims yet “smoke nonstop”, and again when discussing the response of the local people to ISIS. He complains about how “the [civilians] used all the benefits of Islam, they get free charity, they use all these things and they still don’t consider themselves a part of the Islamic State…”

“It’s we and you, dewla and awam,” he finishes in disgust, using ISIS’ preferred Arabic terms for “[Islamic] State” and “commoners” to emphasise the divide between IS militants and ordinary civilians. It’s the only time in our two-hour conversation he uses the word “we” to describe ISIS.

As the war turned against ISIS, these tensions heightened. “ISIS destroyed itself,” Lukas says. He claims he started a religious bookstore to support himself, but had his stock confiscated and destroyed by the Mujahideen. “The Iraqis manage everything,” he goes on. “The foreigners are treated very bad[ly]. They told us in our faces, ‘why you want to live? Why you want to eat? You came to die.' Ninety-five percent of foreign people in ISIS areas [were] talking openly against ISIS. People talked like this three, four years ago, but in secret, between people they trust.”

Alexander concurs: “A German sister got imprisoned by [ISIS] and got tortured until her whole body was full of wounds, because she wanted to leave… Before they captured everyone who wanted to leave, but as the ISIS area got smaller and smaller they couldn’t hold them anymore.”

A moment of relief came when news broke of Trump’s decision to withdraw American troops from the ongoing war against ISIS. “[ISIS] celebrated, they announced it from the mosques,” Lukas recalls. “They said ‘SDF cannot do anything against us anymore.’”

Though ISIS have all but lost the ground war, these celebrations serve as a reminder of the continued presence of thousands of ISIS supporters in sleeper cells across Iraq and Syria. “The idea of ISIS is still a threat, for sure,” Lukas says. Asked if the local population has rejected ISIS’s ideology, Alexander is sceptical: “If they wanted to leave [ISIS territory], they would have left.”

Kurdish protesters in London demonstrating in February 2018 against a Turkish military operation in Afrin (WENN Rights Ltd / Alamy Stock Photo)

According to Lukas, “the southern area of Turkey is still full of ISIS members,” while in the dying days of the war ISIS fighters trapped by the SDF have been requesting transfer to Turkey. Both men say it was “easy, very easy” for them and “all the foreign fighters” to cross the Turkish border.

The question of ISIS’s survival therefore turns on the threat of a Turkish invasion. Since last year’s invasion and occupation of the Kurdish region of Afrin, Turkish-backed militias have been imposing sharia law, kidnapping, torturing and executing civilians, and committing human rights violations possibly amounting to war crimes, according to Amnesty International.

At the least, a similar invasion of the rest of Rojava would destabilise the region and create the type of chaos in which ISIS thrives. France last month announced it will bring back 130 suspected ISIS fighters to face justice in its own courts, fearing they will otherwise be lost in the chaos of an unfolding Turkish invasion.

So far, other Western nations like Ireland, Germany, the UK and the US have failed to follow suit. The autonomous administration in Rojava has repeatedly called on Western nations to take responsibility for the thousands of foreign national ISIS fighters currently in its care, but these pleas have largely been ignored. And so the Kurdish-led forces who struggled for so long to wipe ISIS off the face of the earth have been left responsible for its remnants. “I know it’s going to be a trial for me, but I want to go back,” Alexander says. “It’s still a warzone here.”

As Alexander and Lukas confirm, SDF treats its detainees humanely, but the danger North-East Syria is under means there is no guarantee they will be held securely for much longer – much less that they can be brought to trial and held to account for their crimes. The infrastructure is simply not in place.