The persistent belief in Western policy circles that there is a “moderate opposition” in Syria — reiterated at the close of a NATO summit meeting in Wales on Sept. 5 — warrants serious scrutiny. The very notion of a “vetted” opposition has an absurd ring to it. It assumes that moderation is an identifiable, fixed element that can be sorted out from other, tainted characteristics. It further presumes that the vetting process will not stain those being vetted. It takes as a given that Western-backed opposition will prevail and in turn provide the basis for a happier and better Syria.

There is little to support any of these beliefs. The most effective forces on the ground today — and for the foreseeable future — are decidedly nonmoderate. This is not primarily because the West has let down the Syrian opposition, but because the conflict now sweeping through the Levant is grounded in elements that have little to do with the presumed struggle between moderation and extremism.

Sunni jihadists have been successful precisely because of their insidious appeal to deep-rooted societal and religious instincts and their ability to evoke symbols that elicit a genuine response across the Sunni world, despite their brutality. Anti-Shiite sectarian sentiment adds to their appeal; they have a substantive ideological overlap with Al Qaeda (which disavowed ISIS in February) and with other Syrian rebel groups, like the Saudi-backed Islamic Front, the gulf-financed Ahrar al-Sham and the Qaeda-associated Nusra Front.