The real secret of the Roman Empire was that the army built the roads and aquaducts, and that the locals found these to be well worth the cost of paying for them, politically and financially.
Of course, the other thing the Romans did was cut up the Kurds into four separate nations, and the area was always a pain in the butt...
Divide and conquer.
I truly hope we end up with about 10 or 11 states in the new Iraqi Confederate Government.