The little book "Ausbruch der Kunst - Politik und Verbrechen II" includes a 24 page essay by art critic Boris GROYS entitled "Terrorism as Profession".
GROYS' basic idea is that terrorism is a modern profession similar to web designer or consultant. Put simply and in his own words "without media, there would be no terrorism." GROYS goes back to the "first terrorists" in Russia, namely Boris SAVINKOV to show that one becomes terrorist, because it is "possible" simply by creating opportunities and access. For me personally, GROYS is the master of abstract thinking and reading his views on terrorism from the perspective of art history is refreshing.
And it is totally applicable. For example, ISIS gets so many supporters from the European Union because it is easy and relatively cheap to travel to Turkey and cross the border to Syria. The opportunity is there or to put it in GROYS words "where career can be made, it will be made". If you want to join Al-Qaeda, how would you do it? Probably to to Pakistan and try to cross the border to Afghanistan. But this is much more expensive, you need a visa, etc.
One should never underestimate the appeal of religion and afterlife and everything else that might trigger someone to join a terrorist organisation. But we should also not overestimate it and get caught up in discussions about the definition of terrorism and its connection to religion and so on. If we can keep it simple, why shouldn't we do it.
This text is in German. You can contact me if you want more information.