Here is probably the report closest to what the Iraqi government has to say about the ISIS movements it its country. The below quote is amazing clear and unbiased.
Although this offensive is a clear demonstration of the strength of ISIS and the weakness of the Iraqi Army, the swift capture of entire cities has largely been allowed by the ambivalence of Sunni populations and the assistance of local Sunni militant groups, former Baathists and Sunni tribal militias, who perceive PM Malikis policies as sectarian and see ISIS as a lesser threat to their interests.
Read more @ Weekly Security Update, 10 ? 16 June 2014 | Iraq Business News