This article first appeared in the Volkskrant. It has been translated by Abigail R. Esman and published with permission from the editors.

As a teen, he himself was a radical Muslim. Now Montasser AIDe'emeh, is one of the best-known jihad experts in Belgium. It has been a long fight.

On a Thursday afternoon in a Belgian café, the Palestinian-Flemish jihad expert Montasser AIDe'emeh, 28, warns that IS [the Islamic State] is a long way from being defeated. "IS is under pressure in Mosul and Raqqa, but they view attacks in Europe as an escape from the morass. With European attacks, they reassure their supporters: see, we can still hit back."

Greta Riemersma: So the worse it gets for IS in the Middle East, the more attacks IS will stage in Europe?

Montasser AIDe'emeh: Yes. IS wants to create as much pain, sorrow, and polarization as they can. They will continue to dig deeper. A chemical or poison gas attack is also a possibility.

GR: Isn't that fear-mongering?

MA: (deep sigh) Sometimes I feel like I am crying out in the desert. I don't want to make people afraid. I am realistic. There are chemical weapons in Iraq and in Syria. Anarchy reigns in both countries. Central authorities are shaky. The question now is: which camp has the weapons? I am 100 percent sure that international intelligence agencies take into account the possibility of a gas attack. IS is capable of anything.

Two days after this conversation, seven people are run over and stabbed. It is the eighth attack on European soil this year. Through the telephone, AIDe'emeh is practically screaming. Is it clear yet that we've underestimated ISIS in Europe? Great that Prime Minister May wants to crack down harder, but why only after three attacks in Great Britain? "What a pamper policy. We are at war with IS."

Suddenly he is quiet. Odd noises come through the phone. "Not an attack," he says. "I'm in the carwash." It's a relief to the person on the other end of the line. AIDe'emeh has been on IS's black list since after the Brussels attacks, when he posted a selfie in military garb on Facebook along with the text, "I volunteer for our British military." Recently, a security expert told him to be careful. Even his family doesn't know where he now lives in Belgium.

Back to the conversation from last week, when the Manchester attack was still the most recent. Subject of the discussion: what can European countries do to stop ISIS? Place: a café, somewhere in Belgium – not difficult to understand why AIDe'emeh permits only this vague description. He chooses a seat that gives him a good overview of the entire room. For the rest, he seems relaxed. "I'm not afraid," he says. "I feel stronger than ever."

AIDe'emeh is known in Belgium as one of the top jihad experts. He is working on a dissertation on jihadist ideologies at Radbout University in Nijmegen [The Netherlands]. For his research, he was able to win the trust of countless radicalized Belgian and Dutch Muslims. His insights carry additional weight given his own background: as a middle-schooler, AIDe'emeh used the Israeli flag as a doormat, and had plans to join the militant Shiite group Hezbollah. He overcame his hate, and since has helped other youth to do the same.

But he is also controversial. Last summer, he stated in [Belgian daily] De Morgen that he had worked for half a year for the Belgian secret service. Since then, radical Muslims have seen him as a traitor, and his cell phone is full with messages calling him an "ass-licker," "hypocrite," and "apostate." Even some politicians avoid him. "They don't know quite where to put me," he says.

What inspired him to join the secret service, and then to admit it in public? For his dissertation, he spent two weeks in 2014 with Dutch and Belgian jihadists in Syria. That caught the attention of the secret service, who asked him to become an informant. AIDe'emeh agreed. "I wanted to serve the Belgian people. With my information, I could help in the fight against IS."

In early 2016, he was arrested for having shown willingness to sign a statement of de-radicalization for a radicalized youth. That statement would then allow the young man to be released from prison. But as an informant, he explained to an investigator in an off-the-record statement, it was his hope this would bind the young man to him. But the result was something else: the secret service ended their collaboration with him for talking about his informant network. AIDe'emeh then felt forced to explain publicly how he had become a suspect. At the end of last year, he was sentenced to six months probation for making false statements. AIDe'emeh has appealed; the hearing will be in September.

GR: Does it bother you that it went this way?

MA: No. I still inflict pain on my enemy, IS, every day: by keeping young men away from them, for instance, by holding intellectual debates, by raising ideas.

GR: What can Europe do against IS?

MA: Everyone can do something. We must all be citizens who take responsibility, and transcend the polarized debate. If I look at the hate and frustration people spread on social media, it's clear that they are deeply-rooted. Muslims are constantly hearing "Taqiyya, taqiyya, taqiyya," or "they can't be trusted." Hey, guys – it's getting boring. What are you doing to prevent an attack? With all your hate, you're not creating a safer society. On the other hand, radical Muslims carry on about "apostates" and "unbelievers." Twitter is a garbage dump. Take it easy with people. Be friendly.

GR: Before the attacks in Manchester and London, people who lived in the attackers' neighborhoods tipped off the intelligence services. Is that what you mean as well with "being a good citizen"?

MA: Absolutely. Do you know what the difference is between Morocco and Western countries? Many people there have contact with intelligence agencies. They are the front line of the fight against terror. You have it in Jordan as well. But it doesn't exist in Belgium. I have the feeling that I'm one of the very few. But I think: if the metro is safer through my work, then I've protected the people who ride it.

GR: Systems like that can derail, though; think of the former East Bloc. If everyone is watching everyone else, you get total mistrust. Don't you find that dangerous?

MA: In these times, we need civilian infiltrators into radical milieus, because intelligence agencies can't easily get in. Naturally, these have to be good legal frameworks for this; we don't live in a dictatorship, fortunately. But what is wrong with it? Western governments don't know much about jihadists, so all information from civilians is welcome.

GR: But the tip-offs to intelligence in Manchester and London didn't help.

MA: Intel in countries like Great Britain don't have the ability to arrest people on the basis of ideas. In my opinion, that should change: lock up anyone who praises terror groups or recruits people for them, ban organizations that undermine the law. Change the laws to make this possible. IS men are radical; you have to be radical as well to fight them.

GR: In the book that journalist Jan Lippens wrote about you, The Way to Radical Reconciliation, it seems that you see the solution to the problem of extremism mostly in the Muslim community.

MA: I come out of that community, I specialize in Islam and jihadism, so forgive me if I mostly speak to those people. But everything I say comes from love, concern. I don't hate Muslims; if I did, I'd hate my own family. What is the message in all my texts aimed at Muslims? Free yourselves. Be happy.

GR: Free yourself from what?

MA: Immaturity. Hypocrisy. I am always in that community, you know? Day and night. And then I hear: the problems with IS are the fault of the Jews, or of the West. But if someone points to the Muslims, it's too close for comfort. That's inconsistent. Some Muslims say: we are oppressed everywhere. But Muslims also oppress their own people. Zionists oppress Palestinians, but in Palestinian families there is also oppression. So long as these people don't free themselves from this kind of immaturity, there will never be liberation. Begin with yourself.

GR: Are there others involved in the radical reconciliation you're pursuing?

MA: "We need to stop pointing to others. It's too easy to say: IS-fighters have nothing to do with Muslims. These youths sat in our Muslim communities before they left for Syria, or before they committed attacks here. They are created by a discourse, a mentality, in the community. Suppose that Abdeslam, the terrorist behind the attacks in Paris, was born and raised in a native Flemish family; then he probably would never have been a terrorist. That's something we have to recognize.

GR: But you can't hold every Muslim responsible for each nutcase that commits an attack.

MA: No, but I do feel that all Muslims have a responsibility to denounce the hypocrisy in our Muslim society. And we also have to look at the role of parents. If their children don't learn to reconcile with the secular culture in which we live, then they're busy with the wrong things. No one has met more parents of jihadists in Western Europe than I have – tens of lovely, friendly people. And yet I still say to them: Do you realize your children live in any entirely different reality than the one in which you raised them? They're torn between two worlds. You need to understand that. It can contribute to radicalization.

GR: You've also raised the discussion in Belgium about the angst that Muslim children are experiencing. You said: This is an underexposed aspect of radicalization. Can you explain?

MA: It's about stories that are, among other things, spread via films on YouTube and by imams. They're not in the Koran. They say things like that if you've lived badly, your grave will become narrower after you die. There will be snakes and torture, you will be destroyed. Children in Brussels schools started crying when they told them. I've talked with them a lot. The deputy chairman of the Muslim Executive Council, the responsible organization of Muslims in Belgium, downplayed the whole thing. According to him the stories are like Halloween. But soon after, the Executive Council admitted that Islam teachers were being trained to spread this vision of god. That proves that I had a point.

GR: So the Muslim Executive Council clearly listened.

MA: Yes, but do you think these people listened to the essential points? The problem is: within the stories is a martyr, someone who dies for God, the only one who will not be punished in his grave. That's not a link to terrorism?

GR: Are you maybe too direct in your criticism of the Muslim community? There are so many Muslims who are not quite as enlightened as you are.

MA: I know. And there are fantastic Muslims. Among them I often hear them speak the same criticisms I do. But they don't come out with them. They have to reach out to me. Why is that I stand alone?

GR: Maybe because you generalize? You've said: The intellectual level of the Muslim community is pathetically low. Is that really going to bring people to your side?

MA: You know, many Muslims call for diversity in society. But as soon as a Muslim appears who dares to call out the situation, who breaks taboos, as I do, they are the first to argue against diversity in their own community. I can't deal with the hypocrisy.

AIDe'emeh now works full-time by the Scholengroep Brussel, which represents all Dutch-language schools for students between ages six and 18. He gives classes in critical thinking, including critical thinking about Islam. He's created a prize, the Wise Owl, that he gives to the student who best exemplifies the critical spirit. This is how he currently fights against IS: teaching Muslim children to think, and how they can free themselves. "Those kids touch me," he says, rubbing his eyes.

It is easy to say: IS-fighters have nothing to do with Muslims. But these kids sat in our Muslim community before they went to Syria.

AIDe'emeh grew up with a father who had fled what is now Israel in 1948. The village where the Palestinian family had lived for generations, Sabbarin, was destroyed, and father landed in Belgium via the West Bank and Jordan. He continued dreaming of a return to the lost land, and transferred his hatred of Jews to his son. At around the age of 17, Montasser sought his vengeance. "I was killing Israeli soldiers with pleasure."

But thanks to a visit to Auschwitz, AIDe'emeh began to see that the lot of Jews through the ages was much like the lot of Palestinians today. It was a universal suffering. He no longer wanted to feel that hate, or the longing in vain for a country he never even had. In 2014, he planted an olive tree on the barren plain that had once been Sabbarin, and went to Jerusalem, where he made contact with Jewish youth.

GR: You have no land to return to. Does that explain why you are so connected to Belgium, and will do anything for that country?

MA: I have nothing but Belgium. That strengthens my feeling for this country. But even if Israel should say tomorrow: Come live here, I wouldn't go. It's the past. It makes no sense to be constantly busy with other places, other things. I have witnessed what that did to my family. My father is completely traumatized. So are many others in that situation. It's enough.

GR: After the attacks in Brussels you were completely out of touch. You went wandering in military uniform through the woods behind your parents' home in Baardegem. What was going on with you?

MA: Yeah. I was completely broken. Maybe I'm too empathic. I could visualize how people in the metro right by house were killed. I felt lonely. But also realize: I had been arrested just before that, and the security agencies abandoned me. While I was only busy doing the right thing. I was one of the best informants of Belgium. That's just fact. I received numerous bits of information every day. I was in contact with all the guys. When I wasn't permitted to go further, I had tears in my eyes. And then came the attacks. I begged the agency: Please, give me an assignment.

GR: And? Do you work for them again?
MA: No.

GR: You were in North Iraq over last New Year's. You were just a few meters from the IS front in Mosul. What did you learn there?

MA: Sooner or later, it will all explode. Do you really think that people who are not now behind Assad won't soon support him? And if it escalates, the whole region will go with it, including Israel. The political leaders of Israel don't realize that their current policy is dangerous for the people who live there. There is a chance to establish peace with the Palestinians, because even Hamas has retreated to the borders of 1967. But I don't believe that the Israeli leaders will take that chance.

GR: And if it explodes in the Middle East?

MA: Then the big question is how far we in Europe will be swept up into it. That depends on all of us. I've noticed that everyone considers himself a victim, either from angst and hopelessness or from stigmatization and mistrust. Take responsibility, change a negative experience into something positive. I did that as a young boy. What I can do, anyone can do.