Ah ha! So Christianity, as ever, is a special case. What a surprise!
Wahhabi Islam exists primarily in Saudi Arabia. However, the Muslim Brotherhood (a group which advocates an extreme political form of Islam), exists in all of those countries (except Iran of course).
I don't know what "pattern" you're looking at, but the one I see is one of poverty and political turmoil. Both are catalysts of extremist religion.
In any case, you have yet to demonstrate that all Muslims are extremists...