I have thought of that, but Bagdad is a huge multi-ethinc mix. It wont divide neatly. Splitting the country would almost certainly lead to awful bloodshed in Bagdad. Also, the oil is not distibuted evenly - some groups wont want to split.
It may end up Balkanising, but the process will be very ugly. But, that may in the long run be the only viable stable solution.
