Olivier Roy's take from a conference organised by the German federal police (via Kenan Malik):
9) The religious dimension.
The revolt is expressed in religious terms for two reasons:
– Most of the radicals have a Muslim background, which makes them open to a process of re-islamisation (almost none of them being pious before entering the process of radicalisation).
– Jihad is the only cause on the global market. If you kill in silence, it will be reported by the local newspaper; if you kill yelling “Allahuakbar”, you are sure to make the national headlines. The ultra-left or radical ecology is too “bourgeois” and intellectual for them.
When they join jihad, they adopt the Salafi version of Islam, because Salafism is both simple to understand (don’ts and do’s), and rigid, providing a personal psychological structuring effect. Moreover, Salafism is the negation of cultural Islam, that is the Islam of their parents and of their roots. Instead of providing them with roots, Salafism glorifies their own deculturation and makes them feel better “Muslims” than their parents. Salafism is the religion by definition of a disenfranchised youngster.
Incidentally, we should make a distinction between religious radicalisation and jihadist radicalisation. There is of course an overlap, but the bulk of the Salafists are not jihadist, and many jihadists don’t give a dam about theology. None of the radicals has a past of piety.
More here (pdf).