Let me be more succinct. ;-)

The West is not sending armies into Islamic nations because we have a few ignorant religious nuts here who believe in the Rapture and the End of Days.

The Islamic populations are not striking voilently back against the Western occupiers because they have a few nuts who believe in establishing a Universal Caliphate.

Such nuts do exist. Yes. And they cause much harm. But they are not the primary source of the "War on Terror", they're merely reacting to it in various ways and getting involved in it according to their own prejudices.

Without the primary geopolitical causes of this war already being in place to drive the conflict, those few nuts on either side would find very little backing or support for their wild ideas and their influence on the situation would dwindle away to virtually nothing.