A standard riff is developing among the rightwing commentariat in the US when discussing Europe’s 15m Muslims: they are the potential enemy.

Largely marginalised in low-growth economies, culturally adrift in secular, permissive societies, cut off from their families’ roots in North Africa, many of these Muslims are poor, angry, disorientated and prey to radicalisation by al-Qaeda extremists. The “intifada” launched by rioting Muslim youths in France’s suburbs last November and the murderous bombing campaign conducted by “home-grown” terrorists in London last July are just a foretaste of things to come.