Mark Steyn makes an interesting observation about the cultural “bilingualism”:
Years ago, apropos a Spanish-language payphone in Vermont, I said I couldn’t understand why any country would voluntarily become bilingual. If you happen to find yourself in one for historic reasons, you make the best of it. I like anglophones and I like francophones but, if I were designing a jurisdiction from scratch, I wouldn’t include large numbers of both on the same patch of land. Not because they’ll be killing each other but because it’s a significant impediment to civic cohesion - because, for most people, it will mean you can’t share the same jokes, the same cultural allusions. In Quebec, they used to call it the “two solitudes” - which is a good way of putting it: parallel societies.
Islam is bilingualism on steroids. When the community reaches the size it’s now at in Yorkshire or Malmo or Rotterdam, it has the ability to self-segregate and you wind up on the road to “two solitudes”, parallel societies. (That partially explains the second- and third-generation disassimilation Derb references.) For example, we think of Amsterdam-to-Detroit as a flight between two western cities. But if you’re Muslim it’s a flight between two outlying provinces of the dar al Islam - the fast Islamifying Amsterdam and Dearborn, Michigan.