And the whole issue with extremism is complex. One of the issues no one has yet covered is that extremism is strengthen by the failures of pro-western, secular governments. Image if you and your parents lived in 3rd world conditions in an oil rich nation. Even if you were well off, you would feel some type of way of how inept your leaders and government are. This where religious extremist come and fill a void and use their "divine right" as a recruiting and governing tool. The problem becomes is that the people that oppose these extremist are threaten by extreme violence, another group doesn't care, and the last segment buys into this doctrine of these religious nuts. Couple with the fact you are financially backed by some rich people (who have their own personal agendas) now you have the money, guns, and structure in place to enact your power.
Too many Arab and South Asian secular government are weak and divided, so these extremist come and take over. First with ideology, then committed recruits, finally with being a ruling body.
You have to give credit to these religious extremist organizations, they are efficient and ruthless when it comes to governing and ruling. They provide their citizens with protection and basic infrastructure needs. At the end, most people just expect their government to provide basic protections and fill needs, they could careless about voting or complex human rights (word to Thomas Hobbes and his social contract).