DW: A year ago, during the mass influx of refugees, Angela Merkel became known for her "We can do it" mantra. Large parts of the German population took part in what became known as "welcome culture" after the borders had effectively been opened on September 5. A year on, how would you assess "welcome culture?"

Bassam Tibi: According to Max Weber, a politician has three obligations: 1) a sense of responsibility 2) sound judgment and 3) passionate objectivity. "We can do it" is a slogan. That can be good or bad. I'm not interested in it. What interests me is whether there is an idea behind it. But I don't see the idea. The Koran asks about the main human trait – I am a Muslim, "Don't you have a brain? Can't you reason?" Human beings can reason. And the main purpose of reason is the ability to learn. A year after "We can do it," Angela Merkel interrupts her vacation; she goes to Berlin after the terrorist attacks in July. And you may think, "Now the woman has learned something; now she will be logical when she speaks. And what does she say? 'We can do it.'" I almost fell off my chair. I thought, "What country am I living in?" There is more reason in my home country Syria than in Germany.

In your opinion, what should Angela Merkel have learned?

A German with Syrian roots: Bassam Tibi is critical of limitless immigration

Angela Merkel must know. Last year, there were 58 million refugees worldwide. The number has reached 65.3 according to the United Nations. The majority of these people come from Africa and the Middle East and they want to go to Europe. That is the problem. I am willing to accept 1, 2 or 3 million. But I cannot accept 65 million. It is not possible. We are not talking about morals. Politics is not morality. "Politics is a strong and slow boring of hard boards," as Max Weber says. Merkel has not recognized the problem. Even if you want to receive refugees, but within limits, Merkel says the constitution states no cap. Can you name a law with numbers and percentages? I feel duped! "We can do it" is not a solution, but instead, a moral confession.

You yourself were born in Syria and came to Germany as an 18-year-old in the 1960s. Shouldn't you actually be happy about the Germans' willingness to receive your compatriots - and their limitless willingness?

I am a rationalist; I am not a moralist. A few days ago here in Göttingen I met about 10 Syrians from three groups. I spoke with them. I thought two Syrians from Damascus were great. They had come here when they were 16 and now they are 18. They go to school and they want to learn a profession. They are ordinary people. When we parted I told them, "Do not forget: School always comes first. If you keep going to school, you will graduate from high school. If you study at university, Germans will be wonderful with you." I embrace and warmly welcome these kinds of Syrians.

'Islamists come here'

This morning members of the Muslim Brotherhood were also here. They want a theocracy here in Germany. I told them, "You must be grateful to be here. You cannot impose your ideology on Germans." Then they asked me, "Are you a Muslim?" I said "yes." Then they said, "The earth belongs to God. And Germany belongs to Allah. And Allah gave us Germany. And we will apply God's laws here!" That is not the Islam that I came to know as a tolerant religion in Damascus. Syrians do not exist as an overall category. My experience this morning was that there are Syrians that are good. They are grateful to be here. They will get an education and become successful. But Islamists also come here. They want to spread ideas that our constitution does not allow.

In this context, it is worth looking at France. There, the integration of Muslims and security policy are discussed as two different discussion threads. The language of security policy is used for people who speak the language of violence and Islamism. Muslims who accept the French constitution are embraced and warmly welcomed. Welcome culture is not limitless.

'We can do this' - Merkel at the press conference mentioned by Tibi at the end of July in Berlin

Many refugees wanted to come to Europe but not just Europe, specifically Germany. Why is Germany, of all places, so attractive?

I was in Cairo in March and April as a professor at the American University. Believe me, even beggars on the streets of Cairo know very well that you can get an apartment, monthly payments, and so on in Germany. Germany offers a lot: You can enter Germany without valid documents. You can apply for asylum. If you are rejected, you are still tolerated. So you can stay. You receive welfare benefits. No other country in the world does that. How long can Germany go on like that? How long can it remain peaceful here without social conflicts? My circle of friends consists mostly of immigrants: Persians, Afghans and Turks. And we, as immigrants who have lived here for a long time, are concerned. We are scared. And I can tell you what we are afraid of: The do-gooders of today can become the neo-Nazis of tomorrow. Then we're in trouble.

What are your fears based on?

The great Jewish sources that I admire: Helmuth Plessner, the author of the best book that has ever been written about Germany, " Die verspätete Nation" ("The Belated Nation") and of course my teacher from Frankfurt, Adorno. Both are German-born Jews. And they both say, "Germans are volatile and are always susceptible to the charm of extremes." Look at Horst Mahler: First, he was an RAF (far-left militant group) ideologist and then he ended up with the NPD (The National Democratic Party of Germany, a far-right political party).

Back to the immigrants again. How do you assess the risk that we will have parallel societies in Germany?

That is not a risk. It is a reality! A politician must think in three stages. First, the problem must be named, then facts must be gathered and then a solution must be worked out. Historical experiences are also facts. There was a war in Lebanon between 1975 and 1990 - for 15 years. During that war, thousands of Lebanese went to Germany. One of my best students is a Lebanese who went to Germany with his parents back then. Today he is an important advisor for German authorities and much more faithful to the constitution than many Germans. That is a good example. A bad example is in Berlin. Go there and you will find Lebanese parallel societies where drug dealing, prostitution and crime prevail. And even Berlin's police do not dare go there.

Germans are 'susceptible to the charm of extremes'

German authorities have not learned anything from this historical experience. My experience in recent times has shown that among the people who have come here, there are Syrians who are willing to accept the German constitution, who want to integrate and who want to get an education. But there are also Syrians who are Islamists and they want to live out Islamism here. We must finally learn to distinguish between them. Foreigners and refugees do not exist. There are criminals among the refugees. And among the refugees are people who are traumatized, who we must help and deserve the help.

Between 1973 and 2009, the political scientist Bassam Tibi was a professor of international relations at the University of Göttingen.