To the death
I just found this recent essay from The Guardian on the question of Islam and terrorism, and it's very good.
The last paragraphs:
As I argued in a piece on Ken Loach's film The Wind that Shakes the Barley on Cif two weeks ago, ideology - uncompromising, appealing to purity of thought and action, murderous - is required to give real or imagined wrongs a framework, a cause and both a battle cry and a battle order. You must fight for something as well as against something. And one of the most powerful of such ideologies has been, in very different forms, an appeal to oneness: oneness of nation and ethnos (Nazism); one-ness of class and party (communism) and oneness of faith, state and thought (Islamism).
The ability to dehumanise large tracts of fellow human beings, because they are non-Aryan, or bourgeois, or non-Muslim, lends great strength to the cause: strength enough to cause adherents to gladly murder, and willingly die, for it.