Splitting into three
Making Iraq Three Countries might not be a bad idea. I am sure the Kurds would willing split off, and I bet the Shiite and Sunnis would gladly let them go.
Shiite and Sunnis, on the other hand, would be difficult to separate because I bet there is a lot of the same land they both want. They would have to sit down and fairly divide their two sides of Iraq until each side was happy. Perhaps Baghdad could be split down the middle kind of like the old Berlin.
I am sure oil would be a big issue when it came to dividing things.
But then there is Iran. The UN would have to lean on Iran very hard so that they would not invade any of the three new countries.
But it could work, by gosh, I think it could work.