The conditions laid out by the Islamist are strict: no photos and no audio recording. He also keeps his real name secret as well as his country of origin, and is only willing to disclose that he is Arab. His English is polished and he speaks with a British accent.
He calls himself Abu Sattar, appears to be around 30 years old and wears a thick, black beard that reaches down to his chest. His top lip is shaved as is his head and he wears a black robe that stretches all the way to the floor. He keeps a copy of the Koran, carefully wrapped in black cloth, in his black leather bag.
Abu Sattar recruits fighters for the terrorist militia Islamic State in Turkey. Radical Islamists travel to Turkey from all over the world to join the "holy war" in Iraq or Syria and Abu Sattar examines their motives and the depth of their religious beliefs. Several Islamic State members independently recommended Abu Sattar as a potential interview partner -- as someone who could explain what Islamic State stands for. Many see him as something like an ideological mentor.
He only agreed to an interview following a period of hesitation. But after agreeing to a time and saying he would name a place in due time, he let the appointment fall through. The next day, though, he arranged another meeting time, to take place in a public venue. And this time, he appears: a man with brown eyes behind frameless glasses. He seems self-confident and combative. He orders a tea and, throughout the duration of our meeting, slides his wooden prayer beads through his hands.
SPIEGEL ONLINE: As-salamu alaykum.
Abu Sattar: Are you Muslim?
SPIEGEL ONLINE: Why does that matter? Religion is a private matter for me.
Abu Sattar: Then why did you say "as-salamu alaykum"?
SPIEGEL ONLINE: Because it means "peace be with you" and I see it as a friendly greeting.
Abu Sattar: So you're not a Muslim. I knew it!
SPIEGEL ONLINE: Why is Islamic State so eager to divide the world into believers and infidels? Why does Islamic State see everything as either black or white, "us against the world"?
Abu Sattar: Who started it? Who conquered the world and sought to subordinate all foreign cultures and religions? The history of colonialism is long and bloody. And it continues today, in the shape of Western arrogance vis-à-vis everyone else. "Us against the rest of the world" is the formula that drives the West. We Muslims are now finally offering successful resistance.
SPIEGEL ONLINE: You are spreading fear and horror and are killing innocents, most of them Muslim. You call that successful resistance?
Abu Sattar: We are following Allah's word. We believe that humanity's only duty is to honor Allah and his prophet Muhammad, peace be upon him. We are implementing what is written in the Koran. If we manage to do so, then of course it will be a success.
For Salafists like Abu Sattar, the Koran is the only valid law. They are literalists and refuse to interpret scripture, much less to abstract from it. Abu Sattar and the Islamic State idealize the Muslim community that existed during the lifetime of the Prophet Muhammad, believing that it was the epitome of Islamic practice and that the religion was only able to rapidly expand for that reason. Islamic State would like to revive that interpretation and emulate the early Muslims.
SPIEGEL ONLINE: Do you believe that those who behead others are good Muslims?
Abu Sattar: Let me ask you this: Do you believe that those who launch air strikes on Afghan weddings or who march into a country like Iraq on specious grounds are good Christians? Are those responsible for Guantanamo or Abu Ghraib good Christians?
SPIEGEL ONLINE: You are dodging the question. The events you speak of were not undertaken in the name of a religion and were heavily criticized in the West. Once again: What is a good Muslim for you? What kinds of people are you recruiting?
Abu Sattar: A Muslim is a person who follows Allah's laws without question. Sharia is our law. No interpretation is needed, nor are laws made by men. Allah is the only lawmaker. We have determined that there are plenty of people, in Germany too, who perceive the emptiness of the modern world and who yearn for values of the kind embodied by Islam. Those who are opposed to Sharia are not Muslims. We talk to the people who come to us and evaluate on the basis of dialogue how deep their faith is.
Turkey is seen as a key site for Islamic State recruiting. People from around the world -- from Europe, the United States and Central and South Asia -- travel to Istanbul and establish contacts with the extremists. According to Turkish officials, around 1,000 of the country's citizens are also fighting for Islamic State.
The government in Ankara denies that it is supporting Islamic State, but has in the past allowed jihadists to travel to Iraq and Syria via Turkey . There are also indications that the extremists receive food, medical supplies, weapons and munitions via Turkey and that injured terrorists have been treated in Turkish hospitals.
In the last three years, Turkey has been actively seeking the fall of Syrian autocrat Bashar Assad and has been supporting all groups fighting against him, including Islamist groups. At the very least, it tolerated Islamic State recruitment activities within Turkey.
Abu Sattar periodically glances around to see if he is being watched. He says he is able to continue recruiting, but that "a bit of restraint" is necessary.
SPIEGEL ONLINE: There are an estimated 1.6 billion Muslims in the world today. Many are very democratic, some are liberal while others are conservative and, just imagine, there are heterosexual Muslims and homosexual Muslims among them. Most of them do not share your ideology. But you act as though there were only one kind of Muslim, namely those who think like you do. That is absurd!
Abu Sattar: Democracy is for infidels. A real Muslim is not a democrat because he doesn't care about the opinions of majorities and minorities don't interest him. He is only interested in what Islam says. Furthermore, democracy is a hegemonic tool of the West and contrary to Islam. Why do you act as though the entire world needs democracy? And when it comes to homosexuality, the issue is clearly dealt with by the Koran. It says it is forbidden and should be punished.
SPIEGEL ONLINE: Such statements help cast suspicion on all Muslims. In many countries, they are under pressure to distance themselves from Islamic State even though they have nothing at all to do with terror.
Abu Sattar: So? Are they speaking out against us? (Laughs) I think we enjoy much more support than you would like to believe. Those who demand that Muslims take sides are totally right. We go even a step further: All people should disclose whether they submit to Allah or not. Those who are against us are our enemies and must be fought. That includes people who call themselves Muslims but who don't lead their lives as such -- people who drink, who don't pray, who don't fast, who have constantly changing partners and who are unable to recite the Koran.
SPIEGEL ONLINE: There are many Muslims who have consciously chosen such a lifestyle.
Abu Sattar: That may be true, but that is not Allah's will. When we someday have power, inshallah, in the entire world, then Sharia will be imposed. Such people will then have to atone for their behavior.
Religious fundamentalism is as old as religion itself. Islamic State, however, is applying it with the most brutal of consequences. A self-contained worldview that clearly delineates between good and bad, friend and foe, makes it simple for its followers to find their way in a complicated world. Muslims who interpret Islam differently than the Salafists are simply declared to be unbelievers, a practice of excommunication known as "takfir." For those declared unbelievers, it is akin to a death sentence because turning away from Islam is forbidden. The extremists have also shown no compunctions about using religion to justify war crimes. In Abu Sattar's view, all means are legitimate in the fight for "true faith." It is an approach that thousands of people clearly find attractive.
SPIEGEL ONLINE: You kidnap non-Muslim women and turn them into sex slaves . You crucify or behead those of other faiths, including children. How does that conform to Islam?
Abu Sattar: Why didn't anybody get upset about the many people that Syrian President Bashar Assad has on his conscience? But now that we want to establish a caliphate, it is suddenly a problem? To answer your question: It is every Muslim's duty to fight those of a different belief until only Allah is worshipped around the world. Everybody has the opportunity to accept Allah and to change to the right path. (Recited in Arabic from the Koran, 5. Sura, Verse 33) "The recompense of those who wage war against Allah and His Messenger and do mischief in the land is only that they shall be killed or crucified or their hands and their feet be cut off on the opposite sides, or be exiled from the land."
SPIEGEL ONLINE: Most non-Muslims aren't waging war against anybody. Billions of people, no matter what their religion, are living peacefully with each other, or at least next to one another.
Abu Sattar: (Once again recites in Arabic, this time Sura 4, Verse 89) "They (the Unbelievers) wish that you reject Faith as they have rejected Faith, and thus that you all become equal. So take not protectors or friends from them till they emigrate in the Way of Allah. But if they turn back from Islam, take hold of them and kill them wherever you find them and take neither protectors nor friends nor helpers from them."
SPIEGEL ONLINE: You are avoiding the question by confronting a complex reality with religious texts. But if you really want to conduct such an argument: It also says in the Koran that there is no compulsion in religion. In a different spot it says that one is not permitted to "transgress due balance" because God does not love imbalance. What you are doing is a transgression of balance.
Abu Sattar: Yes, that is in the second Sura. But it also says that one should kill or expel unbelievers wherever one finds them.
This is a typical strategy employed by fundamentalists: They choose those sources that support their position while ignoring those that contradict them.
Abu Sattar says that he has been responsible for "several dozen" young men joining Islamic State. He says they were strictly separated according to their countries of origins and would remain separated during their training in camps in Syrian territory. Contrary to some reports, he emphasizes that no training takes place on Turkish soil. Men with battlefield experience, such as those who fought in places like Chechnya or Afghanistan, are particularly highly valued.
Islamic State concentrates exclusively on the fight and the implementation of their version of Islam. The militias even reject mosques because they distract from faith. Monuments and works of art are likewise destroyed because they see them as idols.
SPIEGEL ONLINE: In the golden age of Islam, there was music, dancing, painting, calligraphy and architecture. Yet you are propagating an Islam free of culture and art. It is time to discuss religious content and find a modern interpretation, don't you think.
Abu Sattar: It is not up to us to interpret God's word. There have been repeated errors and lapses in Muslim societies. That which you refer to as the "golden age" was one of them.
SPIEGEL ONLINE: Then you should at least be in favor of allowing people to read the Koran in their own language so that they understand how they are supposed to live. Most are unable to speak or understand Arabic. Do you believe that the many calls for fighting and killing would be well received were people to be able to read them in their own language?
Abu Sattar: It is Allah's word just as it is in the Koran. We are also not allowed to translate it. It is unimportant whether what it says is well received or not. We are not allowed to question even a single word.
SPIEGEL ONLINE: You keep the people uneducated to build up your power. That is a strategy used by all extremists.
Abu Sattar: You have your viewpoint and we have ours.
SPIEGEL ONLINE: But you fight against all those who don't share your worldview.
Abu Sattar: Christians and Jews go after those who have access to raw materials but who prevent access to them. Oil is the best example. The US and its allies are constantly intervening in countries where they don't belong only to defend their prosperity. Is that any better? We aren't fighting because we are greedy and selfish, rather we are fighting for values and morals.
SPIEGEL ONLINE: When one looks at your actions in Iraq and Syria, morals and values are difficult to discern. One gets the impression that your actions are driven by an inferiority complex. The same holds true of your recruits: They tend to be people who feel like they don't belong and finally see an opportunity to live out their fantasies of power.
Abu Sattar: It is not true that only those people come to us who have experienced no success in life. Among them are many people who have university degrees, people who were well-established. But they all see the inequities that we Muslims have long experienced and want to fight against them.
SPIEGEL ONLINE: You constantly speak of fighting. Do Muslims not constantly speak of Islam being a religion of peace?
Abu Sattar: It is when people submit to Allah. Allah is merciful and forgives those who follow him.