Chait's "basic view is that the Islamic world today is not unlike the Christian world before the enlightenment":
It is a culture where notions of liberalism and religious tolerance are largely foreign -- where even the most liberal mass movement that can be found, the Green movement in Iran, has to make its case in religious terms in order to have any chance at legitimacy. I would not blame the mass of Muslims for al Qaeda's terrorism any more than I'd blame the average medieval Christian for the Crusades. Still, an illiberal, non-secular culture like this is far more capable of producing, or even merely accepting, violence against non-believers qua non-believers.
A lot of liberals have an unfortunate tendency to brand as racist any analysis that holds one culture above another. But there's nothing inherently racial in believing that the illiberal culture that dominates the Muslim world is a key source of the problem, just as it wouldn't be racial make a sweeping indictment of pre-Enlightenment European culture.