ISIS is the expression of different social and political phenomena that must be understood separately. One of them is undoubtedly the significant amount of “Western” fighters of which some elements are also at the forefront of their media campaign. By Western I mean people who have lived and were educated in Western countries (mostly Western Europe and the US) either as Muslim minorities or as recent converts (or who knows maybe just random Westerners with searching for a cause).
Most media article and think-tank papers (I haven’t come across any serious academic work on ISIS) have by now narrated the story of their success in Iraq countless time. Their alliance with Sunni tribesmen and former Baath regime establishment is what tipped the balance in their favor. This explains one particular victory but it does not really tell us more on the movement as a whole and on their different political visions and strategies. The easy answer here is that there isn’t one but many visions or strategies. Yet looking at the various media campaigns led by ISIS and the reaction to them coming from Western media outlets is revealing of the extent to which the struggle is framed along “Western” concerns and imaginaries (and subsequently somewhat alien to local Middle Eastern concerns).
I think that a lot of what ISIS represents is a war that a disgruntled minority from the West is waging against their respective host countries. The problem is that the battlefield is not theirs, it is a fantasized one that the West has imagined but could not provide for them. Moreover, these groups cannot wage this war within these liberal countries as they are tightly policed and where these types of political questions cannot be asked. Here is the dangerous dimension of ISIS: it is a movement that fantasizes about a territory (Arab world, Islamic land etc) it does not come from, using ideological toolkit that the West has provided through decades of Orientalist studies. The most scary aspect of ISIS is that it represents everything the West has stigmatized about Islam for decades, nurtured (whether consciously or not) in the suburban areas of European cities among Muslim minorities or even people in search for identities, and internalized by the Muslims themselves.
This also is proof that ISIS knows Western societies very well. It feeds it with what it fears the most: security breaches and pitiless slaughtering of human lives (something that has been already imagined in countless possible ways for decades in Hollywood movies). These members of ISIS grew up feeding on this culture of constrained violence (constrained in films and other cultural productions). Now they have a vast terrain to experiment on.
One drawback of this is that ISIS is one of the many instance that blurs the boundaries between what is Western and “Other” or even “Peripheral” in many ways. It emanates from a Center and tries to imagine a a type of living that was thought of in the center but as the latter thought of the periphery as it was exposed to a myriad of cultural material.