PARIS — Sunday morning, 9 a.m. It's raining in Paris. We meet Boualem Sansal, 66, in a small office in the central Marais neighborhood. Yesterday he was in Warsaw, tomorrow he'll move on from here. Never, he says, has he traveled so much for any other book he has written. This one is called 2084: The End of the World, and in the tradition of George Orwell's 1984, it describes the dictatorship of faith: Radical Islam has taken over the world, erasing all that had existed before.

DIE WELT: Mr. Sansal, your book is pretty dark. At least Orwell had a love story.

BOUALEM SANSAL: In this world of Islamism, love wouldn't have been credible. Orwell was a Christian and Christianity is structured around love. The idea of salvation through love is omnipresent. In Islam, there's only love for God. Women hide behind love, and love is what Islam is fighting against.

How does a Muslim read your book?

A Muslim like me, who is not religious but grew up in a Muslim country, reads it just like you and I would. The West is wrong in believing that all Muslims are Islamist extremists. Many are even more frightened of Islamic extremism than people in the West.

Ever since the attacks in Paris, the West is frightened, too.

Of course. It was just the beginning. After Charlie Hebdo, things were different; the majority could somehow explain that behavior. It had been blasphemy, after all.

The idea being that they brought it on themselves, like the girl in the short skirt who gets raped?

Yes, and that's why the attacks in January didn't wake people up. The Bataclan, on the other hand, was something completely different. People there were attacked for who they are, for their culture, their lifestyle. It was youth, bars, a stadium, places that are characteristic of the West. The Islamist extremists know they can't fight the West militarily. So they need to make the West destroy itself. They are trying to fracture society because they know that if that happens, it will fall apart all by itself.

In France, there are right-wing extremist intellectuals speaking of the "grand remplacement," the repression of Western Christian society by Islam. Where's the difference between that and what you claim is happening?

I think the expression is not well-chosen. It's not about replacing the society, but about fusion: France is about to Islamize.

Is our culture vanishing?

As a democrat, I regretfully see our civilization perishing.

We have sheltered a million Muslim refugees in Germany. What's your forecast?

Germany was completely naive. And in the long run, it's the country that is most threatened.

Why naive?

Because for a long time Germany was convinced that it was unaffected by these problems. Radical Islam, that's France, Great Britain, but certainly not Germany. And because of what happened in World War II, the Germans have a particularly tolerant society. And that was exploited. When Islamist Algerians were exiled, they went to Germany, where they were taken in as political refugees.

What proof do you have that this war of cultures has already started, that the Islamization of German society is underway?

Germany is rich, influential, extremely well-organized. The fall of Germany is what they dream of more than anything else. One nightmare joins another. In fact, many Europeans share Recep Tayyip Erdogan's nightmares.

Are you Islamophobic, Mr. Sansal?

Not in the sense the word is usually used. I don't like Islam, I don't believe in it, and I note that it represents an extreme danger. It will break up our society.

Do we lack the conviction and courage to defend our values?

Islamists fight very bravely for that they believe in. You have to admit that. When it comes to us I have to confess: We're not driven by anything. For the notion of "freedom" we would have once gone to the end of the world, but that's over now.

That's not true, after Charlie Hebdo millions marched in the streets for the sake of freedom of speech.

That was nothing but a spontaneous emotional reaction. It was meaningless, except for the fact that it put the heads of state into the limelight, above all poor François Hollande, who wouldn't harm a fly. In Algeria, we have seen what happens when people are overcome by their emotions: senseless, collective lamentation.

Do we have to take the title of your book literally? "The end of the world," no hope?

You know, sometimes it's the small things, an idea, a sentence, that shed light on other things. In Algeria, the words of the writer Tahar Djaout were what spread like wildfire. They made things obvious for people. He was right. His words were reassuring, eventually.

What was it?

With a humble smile, he said in an interview: "If you speak, you die. If you don't speak, you die. So speak, and die." A week later he was murdered.