Sadly, those not involved are often hurt the worst. Assad is a barbarian, but Alawites as a whole are hardly the worst people in the ME. They are considered infidels by most of the Sunni muslims fighting the regime. The Nusra front are backed, or made up by, Al Quaeda militants.
With MOST of the population being against Assad it is a given that some of the fighters will have terrorist links.