He also gave Americans a chance to decisively defeat a generation's worth of Sunni holy warriors in Arabia. In retrospect, that is the one saving grace of the Iraqi campaign. We defeated them in a stand-up fight with everything they could throw at us, and no one can deny that. GI's slaughtered them until they were sick of dying and ran away in fear. Of course, Obama and the neo-con idiots have frittered that victory away by helping Islamist governments and al Qaida veterans take over in North Africa, but that's a subject for another day.
So if we help the Sunni jihadis get to Syria to fight Assad, really we are just returning that favor, and giving Assad the chance to fight and kill lots of Sunnis.