Crusades are so High Middle Ages.
There is a long history of the Western world trying to understand the Middle East, what motivates its people, how we should deal with them, how we can play the various peoples off against each other. Occasionally we break all their stuff and change their rulers for them.
Having studied the Middle East at school, in military service, and through reading the works of the legions of highly-experienced journalists who try to make sense of it, I have largely given up on trying to understand it from a rational standpoint. Instead, I offer the following 2 simple insights, which I hope will help the casual reader better to understand the dynamics of the region:
1) Monty Python's "The Life of Brian", making the following subsitutions:
Romans = Americans
Judean People's Front = Shia
People's Front of Judea = Sunni
e.g. "We must unite against the common enemy" - "What, the Americans?" - "No, the bloody Shia".
2) CE 2013 = Islamic year 1434.
In the mid-15th century we'd just burned the (Catholic) Joan of Arc at the stake, and witch-hunts were becoming fashionable, so we can hardly get upset about sectarian intolerance or the oppression of women - it must just be a phase! Looking ahead a bit, there's bad news to come.... the Spanish Inquisition was established in the late 15th century. I'd like to think the region will have settled down a bit by Islamic year 2013; perhaps by then they'll be conducting humanitarian interventions on us?