[M]y basic view is that the Islamic world today is not unlike the Christian world before the enlightenment (a time, of course, when Islam was more tolerant and advanced than Christendom.) 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.
First, whatever the unfortunate tendencies of "a lot of liberals", context matters. Marty Peretz is, as he has demonstrated time and again, a racist. Statements asserting the inherent superiority of one culture over another and advocating a "harsh view of Islam", while they may only qualify as regrettably inane when expressed by others, have to be seen in that context.
As to the more general point, there's no question that Islamic faith currently encompasses some deeply objectionable trends. It also encompasses a number of trends that are rigorously and admirably working to elevate human freedom. Asserting a single "Islamic" "world" "culture" is a pretty clear sign that one hasn't really bothered to do the work.
Even understanding that Iran's Green movement makes its case in terms of political rights, why should the fact that the Green movement "has to make its case in religious terms in order to have any chance at legitimacy" count against it? Iran is a fairly deeply religious society, and we shouldn't be surprised that any Iranian political movement should deploy religious themes in making its case.
Such things are not unheard of here in the West:
Well, I don't know what will happen now. We've got some difficult days ahead. But it doesn't matter with me now. Because I've been to the mountaintop. And I don't mind. Like anybody, I would like to live a long life. Longevity has its place. But I'm not concerned about that now. I just want to do God's will. And He's allowed me to go up to the mountain. And I've looked over. And I've seen the promised land. I may not get there with you. But I want you to know tonight, that we, as a people will get to the promised land. And I'm happy, tonight. I'm not worried about anything. I'm not fearing any man. Mine eyes have seen the glory of the coming of the Lord.