In the United States, we’re more like the Swedes than the Japanese. And that’s a problem, or at least a potential problem. Our current political trajectory suggests that we are committed both to relatively high levels of immigration and to a larger and more active welfare state, with many on the Left pursuing an explicitly Nordic model. It may be the case that these policies are mutually exclusive.

None of this is to say you cannot have a decent, stable, and diverse society — the United States is Exhibit A for the case that you can. But there are difficulties. In the earliest days of the American settlement, diversity meant Puritans here and Quakers there, and our institutions were incubated in a deeply and overwhelmingly Anglo-Protestant culture. But it has been a long time since anything like a Nordic level of ethno-linguistic homogeneity has been present here. Up until quite recently, and with the critical exception of the situation of African-Americans, we handled our diversity with the best tools there are: localism, federalism, equality under the law, integration, participation in civil society. But the aggrandizement of the public sector has diminished civil society, multiculturalism has hobbled integration, the centralization of power in Washington has undermined federalism, and the grievance industry chips away at the idea of equality under the law — ask a Korean-American kid applying to Berkeley how that’s going.

And, as with Stockholm’s ghettos and Paris’s banlieues, our relatively high sustained levels of immigration and our inability to integrate immigrants means the persistence of ethnic enclaves — and the sense of separatism, on both sides of the street, that goes along with them.