Well, Linda ... in a lot of ways, I believe it simply comes down to a question of ego and pride. Islamic "civilization" has been stagnant for many, many centuries, now, and their culture's only links to modernity have solely come from sources outside of themselves ... sources they despise and revile. They cannot bring themselves to admit that they are truly mouldering ne'er-do-wells, so, out of abject frustration, they irrationally vent their spleens on everyone else in criminal acts of what are actually, in many ways, expressions of self-loathing.
B.

The essential American soul is hard, isolate, stoic, and a killer. It has never yet melted. ~ D.H. Lawrence