My prediction
Once we depart and leave the Iraqis to their own devices, the country will devolve into civil war and break up into three distinct countries. On the north, we'll have a Kurdish republic with its eye on expanding into southern Turkey. On the south, we'll have a conservative Islamic state with close ties to Iran. In the middle and to the west, we'll have poverty-stricken Sunni state that will be a perpetual font of Al Qaeda recruits.
I dearly hope I am wrong.