VD Hanson says civilizations are clashing. Daniel Pipes says they are not.
National Review asked a bunch of other people what they think, but most of that's just wheel-spinning: the closest any of them come to actually answering the question is when they posit this as a clash between -- here's an original thought -- liberalism and religious extremism. One of them even denies that Islamic societies have risen to the level of a "civilization," which is, of course, extremely helpful... not. There's an awful lot of discussion of the "Muslim world" without defining what that means, and a lot of finger-pointing at "minorities" and "radicals" without defining their relationship to the "civilization" from which they arise.
The very fact that the question has been asked is interesting: why does it matter if "civilizations are clashing?" It matters because of the way in which it frames the "War on Terror" (as Anne Zook says, the war on Islamic Terrorists and Inconvenient States), going back to the hoary old Huntington thesis...
Update: Sepoy, as always, has his finger on the center of the knot. I'm pretty sure that he's making the same point I was, but I'm gonna have to read it a few more times to be sure. Damn, he's good.