Someone had to say it — and German Chancellor Angela Merkel deserves credit for being the one with the courage to say it out loud: Multiculturalism has “utterly failed.”

Multiculturalism is not just a recognition that different groups have different cultures. We all knew that, long before multiculturalism became a cult that has spawned mindless rhapsodies about “diversity.”

In Germany, as in other countries in Europe, welcoming millions of foreign workers who insist on remaining foreign has created problems so obvious that only the intelligentsia could fail to see them.

“We kidded ourselves for a while,” Merkel said in a recent speech, but now it’s clear that the attempt to build a society where people of different languages and cultures could “live side-by-side” and “enjoy each other” has “failed, utterly failed.”

This isn’t a lesson only for Germany. In countries around the world, and over the centuries, peoples with jarring differences in language, cultures and values have been a major problem and, too often, sources of major disasters for the societies in which they co-exist.

Among the ways that people with different cultures have managed to minimize frictions have been (1) mutual cultural accommodations, even while not amalgamating completely, and (2) living separately in their own enclaves. Both approaches are anathema to the multicultural cultists.

Expecting any group to adapt their lifestyles to the cultural values of the larger society around them is “cultural imperialism,” according to the multicultural cult. And living in separate neighborhoods is considered to be so terrible that there are government-financed programs to take people from high-crime slums and put them in subsidized housing in middle-class neighborhoods.

The direct experience of the people who complain about the consequences of these social experiments is often dismissed as mere biased “perceptions” or “stereotypes,” if not outright “racism.” But some of the strongest complaints have come from middle-class blacks who’ve fled ghetto life, only to have the government transplant ghetto life back into their midst.

The absorption of millions of immigrants from Europe into America may be cited as a success of multiculturalism. But, in fact, they were absorbed in ways that were the opposite of what the multicultural cult is recommending today.

Before these immigrants were culturally assimilated to the norms of American society, they were by no means scattered at random among the population at large. On New York’s Lower East Side, Hungarian Jews lived clustered together in different neighborhoods from Romanian Jews or Polish Jews — and German Jews lived away from the Lower East Side.

None of this was peculiar to America. When immigrants from southern Italy to Australia moved into neighborhoods where people from northern Italy lived, the northern Italians moved out. Such scenarios can be found around the world.

It was in later generations, after the immigrants’ children and grandchildren were speaking English and living lives more like the lives of other Americans, that they spread out to live and work where other Americans lived and worked.

This wasn’t multiculturalism. It was common sense.