There is a major framing problem here. Islamic Fundamentalism as we see it now is not something ancient. It is largely a function of political forces of the post-colonial, post-cold war Asia and Africa.
Most people in the West ignore or overlook how ethnic/tribal differences shape what we think of Islam as a whole or how conflicts caused by them are part of the terrorism continuum.
Prior to Iran’s 1979 revolution, the “Islamic World” was mostly nationalist and secular. The premier Middle East terrorists prior to 1990 were the PLO/Fatah. Secular political radicals. With the cold war between Iran and Saudi Arabia, it became popular to use Islam to recruit proxies and extend political power. You can mark the siege of Mecca in 1979 as the official birthday of Suuni Islamicism of the Al Queda/ISIS/Boko Haram bent.
If one is serious about fighting the effects of Islamicism, one has to look past horrifically reductive and overgeneralized ideas about the religion of Islam and look towards the political realities on the ground.