PARIS — France is frightened about many things these days, terrorism above all. But there is another fear — raised recently by prominent politicians on the right and on the left — of slipping into an acceptance of what is often called an Anglo-Saxon multicultural model, in which ethnic communities live separately, even autonomously.

The idea that this model, or “communautarisme,” should be so repellent can be baffling to Anglo-Saxons, largely understood by the French to be British and Americans who, for the most part, stopped thinking of themselves exclusively in such narrow terms long ago.

France’s idea of an Anglo-Saxon model has meant many things over the last century, sometimes referring to liberal capitalism, rampant individualism, consumerism or, in the view of President Charles de Gaulle, the threat of a global hegemony based on American power and the English language.

But today the perceived Anglo-Saxon threat is about the breakdown of France into distinct communities based on ethnic identity. Prime Minister Manuel Valls referred to this obliquely in criticizing a New York Times article about the European experience of Muslim women, who described a day to day “struggle.” Mr. Valls, a Socialist, stressed that “France, as distinct from other countries, does not see itself as a juxtaposition of communities, each with their autonomous path.”