They had been plagued by weak morale. And those regions had beentreated like crap by Malikis government. I heard a possibility some commanders struck a deal with ISIS to have their troops back off. Either way it was pretty sad. As soon as they were engaged anywhere they bolted.
I could see that happening in exchange for some $$$. Then tell your guys were going to die and need to surrender, conveniently have them leaving all the equipment so as to not be picked up as a soldier, etc.
Either way, something like this was bound to happen with such a non-inclusive government, and without us there to babysit. Hindsight is always 20/20 tho lol.