Here’s What a Man Who Studied Every Suicide Attack in the World Says About ISIS’ Motives

This is a partial take on the issue... One needs to delve into the cities and neighbourhoods ( see, for example the study on Jihadism in Daouar Hicher in Tunis) to identify sociological and psychological motives.
In addition, there is a bigger picture: local and Western state terrorism, repression, economic and financial terrorism by local and international agents, decades of marginalizations and humuliation...