How do extremists prevail?

I once tried to read Salman Rushdie's The Satanic Verses, and frankly, I couldn't do it. It just bored me. So I stopped. But that book, and Rushdie's writing in general, even his mere existence, is anything but boring to lots of people out there who would very much like to slit his throat. Over at The Agonist, Ali Eteraz in an interesting and spirited post offers his view as a Pakastini on the reasons for the seemingly infinite energy available in the Islamic world for hating Rushie, but more importantly, on the origins of this energy and how it is directed by political and religious leaders for their own ends.

Eteraz also notes that the resulting images -- apparently insane multitudes rioting and burning anything they can find -- play into the fearful imaginations of right-wing demoagogues here in the West, who take these images as the depiction of EVERYONE in the Islamic world. The outcome is a grim feedback cycle in which the extremists on one side succeed in stirring up the extremists on the other, with the ordinary folks in the middle dragged alone for the scary ride.

In a recent post I mentioned the classic work of Robert Axelrod on the famous Prisoner's Dilemma, in which he showed how the TIT-FOR-TAT strategy -- I'll be nice to you to begin with, and then mimic your behavior in the future, meeting either cooperation or cheating with same -- can arise naturally as self-interested people (or other kinds of organisms or agents of any kind) come to learn that conflict is expensive and that cooperation pays. TIT-FOR-TAT is open to cooperation, and willing to stick its neck out to start it off, but clearly prepared for vigorous self-defense. But I wonder this: what happens in such a scenario if the players aren't single individuals able to act in a consistent way, but a population of individuals with views and aims across the board? Would some elements in a population find it easy to sabatoge the cooperation toward which others are working?

I've often wondered if some of the more long-run inter-ethnic struggles -- Israel-Palestine, and Northern Ireland, until recently, for example -- don't somehow reflect the ability of the more extreme components of populations to undermine the natural cooperation that would tend to emerge between self-interested but competing parties. Without the extremists, perhaps these kinds of conflict would settle down quite quickly. Does anyone know of such work? I haven't seen any myself.