The whole religious thing is bit of a smokescreen which works for both sides. In reality we have Christians killing Christians and Muslims killing Muslims and a bit both ways, what is it all for? The religion of the almighty dollar is at the root of it all - and many states have been known to do some pretty bad things in the pursuit of said dollar. Unfortunately for the Middle East it has lots of oil which translates into dollars - lots of them. It seems to me that certain governments have dirt on their hands and the poor citizens have to pay for the government's misdeeds. Terrorism is the means for the oppressed (= screwed over) to get back at the bully.
I wonder what the ancient Greeks would have to say about certain 'democracies'and what would Jesus and Mohammed say if they walked the earth today? Even the Romans had to contend with terrorism - it wasn't religious hatred but rather people despised being ruled and raped by the great power. Nothing much has changed.....