As I see it the Sunni minority in Iraq and the Sunni majority in Syria are under siege by Shia. ISIS is the one successful Sunni group opposing the Shia. A very large portion of Arab Sunnis at least passively support ISIS, not because they support its extreme ideology but because they want the Sunnis to emerge victorious. A subset of the pro ISIS Sunnis actually support their extreme ideology. What we call the Iraqi military is seen by almost all Arab Sunnis as a Shia army under the influence, if not the control, of Iran. This explains why Turkey...
