As we learn more about ISIS, there is reason to believe that the movement is less an expression of Islam (whatever that monolithic label means) and more a totalitarian expression of a crushed people.
The followers may be true believers, serving as poster-children for the single dimensional media account of crazed fanatics, but a cursory examination of the leadership and organizational structures reveals calculation and sober analysis, as a recent report has noted.
This is a movement whose ideological forms, organization, and practical actions perpetually morph with a utilitarian eye for opportunity, coupled with spiraling and kaleidoscopic patterns of deceit, for the sole purpose of accumulating power. These characteristics have long been pointed out by historians as distinctive traits of the Nazi movement when it was acquiring and sustaining its power. Consider also Bob Altemeyer's famous study of right-wing authoritarian behaviors.
Doubtless, Hannah Arendt, who obsessively studied totalitarian movements, would find this particular movement interesting.
But another thing that historians who have studied the Nazi movement agree on is the fact that Germany's collective economic and political humiliation after WWI, combined with extreme economic hardship and social atomization in the following years, proved to yield fertile conditions for the gestation of Nazi-style fascism.
So then, will it take the eventual dying down of the flames of destruction for there to be any sort of understanding this time?