Those who follow "real Islam" must be exterminated when they attempt to enact their aims.
More or less works for me.
Considering how much attention Islam gets today, it’s interesting to remember that when Herbert wrote Dune in 1965, he based most of his Fremen culture on Islam because it was so exotic and unknown to the rest of the world.
In 1965 nobody ever thought about Islam. Even the Arab conflict with Israel was primarily based on nationalism, not religion. Lots of the Palestinian leaders, for example, were Christians.
BTW, one of my best friends converted to Islam in the late 60s because the Episcopalianism he was raised in was too violent. He has since commented that this was a little frying pan and fire. But the point is that in the late 60s Islam wasn’t perceived as particularly violent, because mostly it wasn’t. (Then.)
In his defense, he joined a branch of Sufism that really is non-extremist. Of course, ISIS would kill him and his fellow sect members immediately.
Would be interesting for somebody to run a search in the last 50 years of the NY Times to see how often Islam was mentioned each year.