DW: After the bloody terror attacks in Great Britain, there are an increasing number of studies being conducted on the cause of radicalization. Britain's Henry Jackson Society, a think tank, has published a report on foreign funding for extremist branches of Islam in Great Britain. Saudi Arabia has been clearly named as one of the greatest supporters. In the past 50 years, Riyadh has invested at least 76 billion euros ($86 billion) in Wahhabi extremism, the ideological basis of extremist and jihadist movements throughout the world. Are you surprised about these findings?

Susanne Schröter: The findings do not surprise me at all. It has long been known that Saudi Arabia has been exporting Wahhabist ideology - largely similar to the ideology of the so-called "Islamic State" (IS). Propaganda material and organizational expertise are being sent along with money. People are being hired to build mosques, educational institutions, cultural centers and similar organizations, so that Wahhabist theology can reach the public – with great success.

Where is this extremism, that is fueled by oil money, most obvious?

The export of Wahhabism got off the ground after the Islamic revolution in Iran. The revolution had dramatically shaken the Saudis. When Iran started exporting its Shiite ideology, the Saudis felt threatened by it. Around that time, in 1979, hardliners seized the Grand Mosque in Mecca. The Saudis launched an ideological offensive and said, "Now we are exporting our own ideology. We will show the hardliners in our own country what we are capable of achieving." Then, they started promoting Wahhabism through intermediaries and organizations like the World Muslim League in different countries throughout Asia, Africa and parts of Europe – for example, in former Yugoslavia where Muslims and Christians fought against each other in the civil war. Wahhabists saw it as a gateway, where money was needed since the Muslim population was ready for a new and radical ideology.

The result is that, in many parts of the world, a radical form of Islam is gaining the upper hand. I have experienced this first hand in Southeast Asia. In southern Thailand, the Philippines, Indonesia, and sometimes Malaysia, it was always said that a special form of Islam was practiced, a much more open, much more tolerant version. There has been a dramatic development towards radicalism over the past three decades. It is perfectly clear that this development has been encouraged by Saudi money. Moreover, young intellectuals have been recruited with generous scholarships at Saudi universities. These people return to their homes after having studied at Saudi universities and suddenly carry out Wahhabi missionary work in all their home countries.

Pierre Vogel, perhaps the most well-known German Salafist preacher, studied on a Saudi scholarship in Mecca. Saudi Arabia has apparently influenced the radicalization process of Muslims in Germany. German media made such claims in December 2016, citing intelligence sources. It was said that religious foundations from the Gulf States, especially Saudi Arabia, supported local Salafist groups in Germany with the approval of their governments. To what extent does this correspond to your research findings?

This is absolutely consistent with our findings. In some cases, state-owned Saudi institutions were massively involved. There was once a Saudi attache in Berlin, Mohamed Fakihi. He had connections to the terrorist cell in Hamburg that carried out the attack on the World Trade Center in New York in 2001. Fakihi also was well connected to Berlin's Al-Nur Mosque, which often attracts attention for being a Salafist hotspot. The attache is now no longer there but back then, it was the first time people became aware of this.

We have seen that Saudi foundations are operating everywhere - partly underground and partly through intermediaries, like Nadeem Elias. Until 2006, he was chairman of the Central Council of Muslims in Germany. This is one of the most important Muslim associations that constantly maintain inauspicious ties with Saudi foundations, including the Muslim World League or the World Assembly of Muslim Youth.

There is also another high-ranking official in the Central Council of Muslims: Ibrahim El-Zayat. Zayat was chairman of the Islamic Community of Germany from 2002 to 2010. We have only scratched the surface. And when people are asked questions, they are always evasive. But it is clear that there are organizations and individuals in Germany who take the Wahhabization of German Muslims seriously.

According to latest report published by the Office for the Protection of the Constitution, a German domestic intelligence agency, the Salafist scene in Germany has now grown to include over 10,000 members. There must be other reasons apart from Saudi support, right?

Of course. Firstly, not only do the Saudis bankroll extremists. Now attention has been drawn to Qatar for doing this. And yes, it is true that Qatar provides funds and Kuwait provides funds. There are also other players in the Gulf Region who support radical tendencies here in Germany - including Iran. Iran has set up an institute in Berlin, where it works as a missionary. I assume that if you observe where money flows, you will be amazed. Germany is generally a place where foreign extremist organizations are active.

Professor Susanne Schröter is the director of the Frankfurter Research Center for Global Islam (FFGI), director of the Institute for Ethnology, principal investigator the cluster of excellence "The Formation of Normative Orders," director of the Cornelia Goethe Center for Gender Research and executive board member of the German Orient Institute.

The interview was conducted by Matthias von Hein.