The days of explaining away religious violence in Islam as the inevitable result of Western actions and attitudes towards Islam are over.

For two decades—ever since the two fatwas issued by Osama bin Laden against America in 1996 and 1998–there has been a populist movement within Islam, mainly (but not only) young, highly ideological, widespread beyond the Arab world, and fed by social media. September 11, 2001, was the first salvo and first success of this movement.

It was, as they say, a paradigmatic moment which radicals ignorantly believed did irreparable damage to the Western psyche. Radicalized Muslims now crave a second moment and will do nearly anything to make it happen. Like their predecessors who engineered the use of passenger jets as bombs, they believe in their own martyrdom and subscribe to a peculiar (but by no means insignificant) strain of Islamic thought that regards the taking…