In a long, rambling statement in September, ISIS spokesman Abu Muhammad al-Adnani expounded on his group’s inherent advantage: “Being killed … is a victory,” he said. “You fight a people who can never be defeated. They either gain victory or are killed.” In this most basic sense, religion—rather than what one might call ideology—matters. ISIS fighters are not only willing to die in a blaze of religious ecstasy; they welcome it, believing that they will be granted direct entry into heaven. It doesn’t particularly matter if this sounds absurd to most people. It’s what they believe.
Too true. Confirmation bias plays its part. And the unwillingness to believe something that's uncomfortable. The great Sam Harris has written elsewhere of a discussion with a professor (Scott Atran) who simply refused to believe that jihadis could be motivated by what they said they were motivated by, simply because that's not the way he felt (here).
The above is from left-of-centre The Atlantic.