To understand France's jihadis, look at where they came from

Eurocrats rarely see Molenbeek, the Brussels commune that has become the focus of police investigations following the Paris abominations — except, occasionally, from the windows of their chauffeured limousines. A canal separates Molenbeek from the monstrous EU buildings of the Schuman quarter; but the two districts are divided by much more than a stretch of gray water.

Brussels is home to two types of immigrants. First, there are those (like me) who are in some way connected to the EU or to its ancillary industries: lobbying, journalism, PR. Then there are the large Turkish and North African populations, connected to their ancestral countries by the satellite dishes through which they watch TV from "home." The two worlds rarely meet, except when an EU official gets into a taxi, or perhaps hires a head-scarfed cleaner.

Few Bruxellois are surprised that Molenbeek is the epicenter of the Paris plot. It's not a uniquely poor district, at least not by comparison with the tower-blocked banlieus — the suburbs that ring some French cities. Molenbeek is run-down, jobless and listless rather than seething. Its local council has a reputation for uselessness. The commune has been under the control of the Left for as long as anyone can remember, and councilmen rely lazily on Muslim votes. But it would be idiotic to argue that growing up in a down-at-heel, dull, vaguely corrupt borough somehow puts young men on the path to mass murder.

Alienation is a common enough phenomenon among second-generation immigrants, pulled between their countries of birth and the sunlit lands of their grandparents' stories. Sometimes, the sense of dislocation becomes a clinical condition: Schizophrenia is eight times more common among second-generation Dutch immigrants than in the general population.