She assumes the three Leeds lads were from Britain's Mirpur population, and may well be right (what was that observation by Emmanuel Todd makes about social volatility and rapidly growing populations where people marry their first cousins?)
But the fourth bomber almost certainly was not, and for this reason among others her piece is not the full story (nor, in fairness does it pretend to be).
The Economist ("The Enemy Within") cites Oliver Roy on "neo-fundamentalism", which may or may not be violent as:
"a broad reaction by Muslims in western countries against their families and background, as well as against their host societies. As Mr Roy portrays them, such Muslims have abandoned the food, music and customs of the 'old country'but still feel repelled by the ethos and values of the 'new country'. Adrift from both, they are attracted by a simple, electronically disseminated version of the faith which can readily be propagated among people of all cultures, including white Europeans".