The point is that being willing to die in the course of carrying out some terrible action to further a cause you believe in is not restricted to any one type of culture or religion. It's very much part of "Western" culture, and has been for a long time.

People don't need to be religious lunatics to be suicide bombers or similar (though if they did it seems clear there's no shortage of religious lunatics around in the USA - not just there, but they do seem to have greater political muscle there than anywhere else outside the Middle East, if the media are to be believed, which of course is always a very big "if").