Ibn Taymiyyah might justify, but what radicalizes Islamists?

Infidels?
Memri

In the MEMRI Daily Brief No. 62 (October 20, 2015), Alberto M. Fernandez describes the "Antechamber Of Jihad: The Media Space From Which ISIS Is Nurtured":

Despite the prolific nature of the ISIS propaganda machine, most media worldwide (even in Arabic, and even that of Islamists) is hostile to the Islamic State. But this is not to say that this ostensibly hostile media does not unintentionally provide a larger framing for ISIS's much more focused and targeted messaging. ISIS adventitiously adapts and uses material from mainstream media, as well as left-wing or fringe anti-American material, extreme sectarian content, and Salafi Islamist material, as part of a witch's brew of arguments and images forming an antechamber for jihad, a prepping for takfiri Salafi jihadism. This is non-ISIS content that shapes the environment for the Islamic State's own special brand.

In case anyone is baffled by such expressions as "takfiri Salafi jihadism," the term "jihadism" means those Islamists committed to holy war, "Salafi" means those Islamists who follow Ibn Taymiyyah in looking back to Muhammad's companions for the proper sort of Islam, and "takfiri" means those Islamists who are so fanatical that they label as "infidel" any Muslim whose ideas diverge from their own. How ironic, then, that the Islamic State relies on so much non-Islamist media for framing its message:

ISIS videos are referential of the media of others, whether mainstream news media or other mainstream sources. In 2012, before it entered the most polished, current phase of its original media production, the Islamic State used news clips from pan-Arab media, from CNN (i.e. a 2007 documentary on human rights abuses by the Iraqi government) and from the BBC (i.e. a 2010 exposé on a fake bomb detector) to make its point. Direct and indirect references to Hollywood movies and video games are still relatively common. Clips from the 2005 Ridley Scott film "Kingdom of Heaven" have been used several times. And, of course, while ISIS is indeed prolific, viewers of all sorts, even potential ISIS recruits, are more likely to see material about, say, a particularly notorious Assad regime massacre of Sunni Muslims or a story involving mistreatment of Muslims from the Western media itself.

In other words, the Islamic State draws its rhetoric from wherever it can - left-wing, right-wing, even from Hollywood . . . . not that any of these were anything other than adventitious excuses. Much of the hatred against infidels comes from various Islamists:

An even more important ingredient in the ISIS Petri dish is the extreme sectarianism promoted by a wide range of (non-ISIS or even anti-ISIS) Islamist voices. These can be antisemitic, anti-Christian, or anti-Shi'a sentiments, images, and videos which complement the antisemitic, anti-Christian and anti-Shi'a rhetoric of the Islamic State.

For specifics, see the report . . .