Decades of consensus about a multicultural society have been thrown into question recently as leading German politicians suggest that minorities living in the country need to do more to fit in.
"The notion of multiculturalism has fallen apart," said opposition conservative leader Angela Merkel in a recent interview.
Many Turks found work during Germany's economic miracle
"Anyone coming here must respect our constitution and tolerate our Western and Christian roots."
It was just one of a chorus of voices, from left and right, among politicians and the media.
The debate centres largely around the three million-strong Muslim community - mostly Turkish, with Bosnians making up the next largest group, followed by people of Arab origin.
It was sparked by the killing of Dutch film-maker Theo van Gogh, and subsequent attacks in the Netherlands on Muslim and Christian sites.
Fears that something similar could happen in Germany were fanned by a TV broadcast in which a secret recording caught an imam telling worshippers that Germans would "burn in hell" because they were unbelievers.
This has been followed by a raft of new proposals for better integration of the Muslim community, against a backdrop of fears that Muslims in Germany inhabit a "parallel society" centred around mosques infiltrated by "hate preachers".
"A democracy cannot tolerate lawless zones or parallel societies," declared Chancellor Gerhard Schroeder. "Immigrants must respect our laws and acknowledge our democratic ways of doing things."
Another politician suggested it should be compulsory for imams to preach in German, and sections of the media have judged that the debate marks the end of multiculturalism.
"It's a quite frank debate on what we Germans expect of those people coming to us as immigrants," says Nikolaus Blome, commentator with Die Welt newspaper.
"If multiculturalism means that it's OK for 30,000 Turks to live in a certain quarter of Berlin, and never leave, and live like they're still in deepest Turkey, then the term is now discredited."
The debate shows a marked swing in the atmosphere in Germany.
Four years ago, a conservative politician was attacked from all sides for suggesting the country has a Leitkultur or "leading culture".
As this previously unacceptable term resurfaced, former Chancellor Helmut Schmidt caused further furore by suggesting that the decision to invite "guest workers" to Germany in the 1960s had been a mistake.
Poor command of the German language among Muslims has been singled out for particular criticism.
When tens of thousands of Muslims took part in a protest against terrorism in Cologne recently, the German politicians who addressed the crowd gave them a blunt message: "Learn German."
A new immigration law which takes force from 1 January contains compulsory language and civic lessons for new arrivals, but critics point out there is nothing for people from ethnic minorities who are already here.
Erol Ozkaraca lives in the Berlin district of Reinickendorf, where the population is a mix of Germans, Turks and people from the former Soviet Union.
Switching off the Turkish TV channel broadcasting into his living room, and taking a contemplative drag on his cigarette, he declares: "Germany has never been a multicultural society. The concept of multi-culturalism was never given a chance here."
Mr Ozkaraca, a lawyer by profession, was born in Hamburg. His father came to Germany as a student in 1949, long before the "guest workers".
"These politicians say: They don't speak German, they don't want to be part of German society, and they have their own structures. But I ask: Where are the courses where we can learn German? Where is the help to integrate us, to show - you are welcome and we want you here?"