No sooner am I settled in an interviewing room in the police station of Kirkuk, Iraq, than the first prisoner I am there to see is brought in, flanked by two policemen and in handcuffs. I awkwardly rise, unsure of the etiquette involved in interviewing an ISIS fighter who is facing the death penalty. He is small, much smaller than I, on first appearances just a boy in trouble with the police, his eyes fixed on the floor, his face a mask. We all sit on armchairs lined up against facing walls, in a room cloudy with cigarette smoke and lit by fluorescent strip lighting, a room so small that my knees almost touch the prisoner’s—but he still doesn’t look up. I have interviewed plenty of soldiers on the other side of this fight, mostly from the Kurdish forces (known as pesh merga) but also fighters in the Iraqi army (known as the Iraqi Security Forces or ISF), both Arab and Kurdish. ISIS fighters, of course, are far more elusive, unless you are traveling to the Islamic State itself, but I prefer to keep my head on my shoulders.

Rumors abound as to summary executions of ISIS prisoners without due process, but of course no one will go on the record to report such abuses of human rights. Anecdotally, we were told about a prisoner who was interrogated for 30 days but only said “Allahu Akbar” (God is great) for the entire month. “Wouldn’t you shoot him?” they asked. One peshmerga gave an eyewitness report about five prisoners captured, questioned, and shot in the head. We spoke to various military leaders who said they didn’t want to take prisoners, since injured bodies are often booby-trapped and kill approaching soldiers; for this reason the PKK has a take-no-prisoners policy. (The PKK, or Kurdistan Workers’ Party, is the Kurdish separatist group based in Turkey and northern Iraq that is on the international terrorism list; in proving themselves indispensable in the fight against ISIS, they have caused a dilemma for Western governments. They are seemingly not so indispensable that those governments have felt compelled to oppose Turkey’s recent bombing campaign against them.)

Another source told us of the futility of holding prisoners for their bargaining power: “With ISIS, there’s no compromise, no negotiation…they’re not interested in prisoner exchange because they believe that they’re better off dead.” Whatever the truth of the behavior of the military and security services, the fact remains: ISIS prisoners are hard to find.

One evening we watch a documentary on BBC Arabic profiling Brig. Gen. Sarhad Qadir, the head of police in the Iraqi governorate of Kirkuk. He is shown policing the town of Kirkuk, personally patrolling the streets and houses, arresting people suspected of fighting for ISIS. Kirkuk, then, seems like a good place to start: At least there are prisoners there, shown by the BBC, no less.

And so my colleagues and I drive to Kirkuk from the capital of Iraqi Kurdistan, Erbil, to meet Qadir. Despite the workload of maintaining security in this uneasy city of mixed ethnicity (mostly Arab, Kurdish, and Turkmen), rife with ISIS sleeper cells, he is welcoming, sending armed guards to bring us in from the highway to the city. We are served tea in his office, and he sits with us for half an hour before we are taken to the interview room with two colonels. (The week after I left the country he and other officers would be caught in a huge car bomb; Qadir was wounded for the fourteenth time in the service of Kurdistan.)

Once the first prisoner is there, and with no possibility of small talk, we launch straight into the research questions I am there to ask, the same questions asked of fighters and non-fighters all over the country, questions I’ve asked in Lebanon too, and which have been replicated in other parts of the world by my colleagues at Artis International, a consortium for the scientific study in the service of conflict resolution. The research is based on cognitive and moral psychology, exploring when and why humans commit the most extreme sacrifices—including their lives and the lives of their families—for abstract causes, for so-called “sacred values.” Our research tries to determine why people will change their minds about these sacred values, and whether and how they will change their behavior in defending them. We hope to find out how to persuade people to abandon violent pathways, though I am fast losing faith in that possibility in this part of the world.

For this trip I am accompanied by senior colleagues; by Scott Atran, an academic based in France; and by Doug Stone, a retired American general who spent over two years in Iraq during the US occupation, interviewing prisoners on a daily basis. This, of course, changes the interview experience fundamentally, crowding the room and giving the event more importance, more formality, but also bringing entirely different questions, emphases, and expertise to bear and so drawing out many different angles on the interviewees. In any case, informality is never going to be achieved with prisoners on death row.

First are questions probing perceptions of the strength of various groups—some of which the interviewee might have sympathy with (although he might not express this). Other groups he would quite clearly consider to be the Other, the Enemy. I bring out a flashcard with pictures of half-naked men on it, ranging from the fairly puny to the biggest bodybuilder—each head replaced by a flag of the Islamic State. Whatever this youngster was expecting, whatever he’s been asked before—this was neither. He looks up, startled, at my colleague Hoshang Waziri—his first human reaction—who begins to explain.

“This is the Islamic State—look, this is the flag here,” Hoshang says, pointing at the bodybuilder and flexing his biceps. “This picture shows the Islamic State as the strongest it could be. Here, they are very, very weak; and here are all the things in the middle. How strong do you think they are?” The boy timidly points at the weakest—to be expected, as he doesn’t want to seem to be a fan—and we move to a similar picture, but with the Kurdish flag rather than the Islamic State flag superimposed on the bodies. “Now the peshmerga: How strong are they?”

The prisoner got the hang of the question, and points to the second-strongest picture. In other pictures, he decides that the Iraqi army is in the middle, Iran a little weaker than that, and America the strongest. (He hasn’t heard of the PKK, despite their repeated victories over ISIS.) We ask him to rank all the forces, using the cards, and then I realize that he is still handcuffed and I ask for them to be taken off. In the ensuing hiatus, with policemen fetching keys and walking to and fro, I try to chat more informally, and finally he looks at me, answering questions in one-word answers as to his age, background, education, family. Slowly, with snippets emerging from the rest of the interview, I piece together a picture that is to be repeated, with only minor differences, with other prisoners we talk to that day, stories familiar to General Stone from during the allied occupation, and to journalists and researchers I’ve spoken to since.

This man is 26, the eldest of 17 children from two mothers (that is, his father had two wives at the same time), from Kirkuk. He completed sixth grade, meaning that at least he was literate, unlike others we were to interview. He is married, with two children, a boy named “Rasuul,” meaning Prophet, and a girl named “Rusil,” the plural of Prophet—indicating the centrality of Islam to his life. He was working as a laborer to support his huge family when he hurt his back and lost his job. It was then, his story goes, that a friend, from the same tribe but only distantly related, approached him with the offer to work for ISIS. The story has been honed through repeated interrogation and the trial, and comes out pat. Life under the Islamic State was just terror, he says; he only fought because he was terrorized. Others may have done it from belief, but he did not. His family needed the money, and this was the only opportunity to provide for them.

Later in the interview we find out just how committed he is to his family, first with flashcards that we use to test the degree of fusion of the individual with various groups. We ask about Iraq, Islam, family, friends, and the Islamic State. The choices are again made pictorially: We use a set of two increasingly overlapping circles (at one end of the spectrum the circles are not even touching, at the other they are fully overlapping, with four circles of varying degrees of overlap in between), and again, they are unexpected and confusing to the prisoner—there is not an obvious “right” answer for most of them. The man is drawn out of his shell in spite of himself, losing his self-consciousness in his concentration and his questions to Hoshang. Eventually he decides that he is almost, but not entirely, fused with Iraq and with Islam, completely separate from the Islamic State (again, to be expected), barely connected to friends (“I have no friends”), and fully fused with his family. In fact, his family is the only group he was fully fused with, a decision that took no time at all. During more informal questioning about his family and tribe comes this telling statement: “We need the war to be over, we need security, we are tired of so much war…. all I want is to be with my family, my children.”

When he has been taken away we have the chance to find out just what he was found guilty of, how they found him, and what the evidence was. He was a master of the car bomb, detonating at least four of them in Kirkuk itself and also one scooter bomb, which exploded in a crowded souq selling weapons, killing many scores of people and also weakening the ability of local residents to fight ISIS. He was found through the capture of one of the financers of the sleeper cells in Kirkuk, who had on him a list of pseudonyms along with phone numbers and amounts of money. The police had this man call each person on the list, a cell of six, and set up meetings, where the police captured them—all of them swept up in one day. When the ISIS bomber saw that they were there “he collapsed; he gave us 5 pages of confession.” He stuck to his confession in court, where he was tried under Article 40, the Iraqi law on terrorism, which carries the death penalty.

Why did he do all these things? Many assume that these fighters are motivated by a belief in the Islamic State, a caliphate ruled by a caliph with the traditional title Emir al-Muminiin, “Commander of the faithful,” a role currently held by Abu Bakr al-Baghdadi; that fighters all over the world are flocking to the area for a chance to fight for this dream. But this just doesn’t hold for the prisoners we are interviewing. They are woefully ignorant about Islam and have difficulty answering questions about Sharia law, militant jihad, and the caliphate. But a detailed, or even superficial, knowledge of Islam isn’t necessarily relevant to the ideal of fighting for an Islamic State, as we have seen from the Amazon order of Islam for Dummies by one British fighter bound for ISIS.

In fact, Erin Saltman, senior counter-extremism researcher at the Institute for Strategic Dialogue, says that there is now less emphasis on knowledge of Islam in the recruitment phase. “We are seeing a movement away from strict religious ideological training as a requirement for recruitment,” she told me. “If we were looking at foreign fighter recruits to Afghanistan 10 or 20 years ago, there was intensive religious and theological training attached to recruitment. Nowadays, we see that recruitment strategy has branched out to a much broader audience with many different pull factors.”

There is no question that these prisoners I am interviewing are committed to Islam; it is just their own brand of Islam, only distantly related to that of the Islamic State. Similarly, Western fighters traveling to the Islamic State are also deeply committed, but it’s to their own idea of jihad rather than one based on sound theological arguments or even evidence from the Qur’an. As Saltman said, “Recruitment [of ISIS] plays upon desires of adventure, activism, romance, power, belonging, along with spiritual fulfillment.” That is, Islam plays a part, but not necessarily in the rigid, Salafi form demanded by the leadership of the Islamic State.

More pertinent than Islamic theology is that there are other, much more convincing, explanations as to why they’ve fought for the side they did. At the end of the interview with the first prisoner we ask, “Do you have any questions for us?” For the first time since he came into the room he smiles—in surprise—and finally tells us what really motivated him, without any prompting. He knows there is an American in the room, and can perhaps guess, from his demeanor and his questions, that this American is ex-military, and directs his “question,” in the form of an enraged statement, straight at him. “The Americans came,” he said. “They took away Saddam, but they also took away our security. I didn’t like Saddam, we were starving then, but at least we didn’t have war. When you came here, the civil war started.”

This whole experience has been very familiar indeed to Doug Stone, the American general on the receiving end of this diatribe. “He fits the absolutely typical profile,” Stone said afterward. “The average age of all the prisoners in Iraq when I was here was 27; they were married; they had two children; had got to sixth to eighth grade. He has exactly the same profile as 80 percent of the prisoners then…and his number-one complaint about the security and against all American forces was the exact same complaint from every single detainee.”

These boys came of age under the disastrous American occupation after 2003, in the chaotic and violent Arab part of Iraq, ruled by the viciously sectarian Shia government of Nouri al-Maliki. Growing up Sunni Arab was no fun. A later interviewee described his life growing up under American occupation: He couldn’t go out, he didn’t have a life, and he specifically mentioned that he didn’t have girlfriends. An Islamic State fighter’s biggest resentment was the lack of an adolescence. Another of the interviewees was displaced at the critical age of 13, when his family fled to Kirkuk from Diyala province at the height of Iraq’s sectarian civil war. They are children of the occupation, many with missing fathers at crucial periods (through jail, death from execution, or fighting in the insurgency), filled with rage against America and their own government. They are not fueled by the idea of an Islamic caliphate without borders; rather, ISIS is the first group since the crushed Al Qaeda to offer these humiliated and enraged young men a way to defend their dignity, family, and tribe. This is not radicalization to the ISIS way of life, but the promise of a way out of their insecure and undignified lives; the promise of living in pride as Iraqi Sunni Arabs, which is not just a religious identity but cultural, tribal, and land-based, too.

An illustration of the less-than-total commitment to the cause of the Islamic State by Iraqis came from the Kurdish peshmerga Gen. Aziz Waysi, commander of the elite Zerevani (“Golden”) forces. He relates an overheard conversation between an ISIS fighter on the battleground and his leader, via a walkie-talkie previously confiscated from an ISIS corpse. “My brother is with me, but he is dead, and we are surrounded, we need help at least to take away my brother’s body,” General Waysi heard, and then the reply: “What else could you want? Your brother is in heaven and you are about to be.” This answer wasn’t what the poor surrounded young man was hoping for. “Please come and rescue me,” he said. “That heaven, I don’t want it.” But they didn’t, leaving him to whatever paradise awaited.

Editor’s note: This article has been adjusted to indicate more accurately the ethnic makeup of Kirkuk and the fact that the Kurdistan Workers’ Party (PKK) is present in both Turkey and northern Iraq.