Thought provoking.
While I would agree with the author that, without Islam, conditions in the region would still make it likely that a terrorist organization would arise, there is no denying the fact that ISIS strongly identifies with Islam, and in fact wants to create a muslim caliphate.

I had a different take on this, Tarnation.  As I see it, when there is unrest, anger and dissatisfaction among the poorer classes of people, there needs to be a 'hook' to encourage them to join a cause.  In this case, religious belief works.  It's happened time and time again throughout history. 

Think of religion and what it is in the general sense, not a specific religion, sect, or denomination.  If you are leading a crappy life and feeling helpless and alone, religion offers hope and a feeling that others share your woes, and thus, you are not alone.

I may not have explained this very well, so I'll think about it some more and come back to the topic later.