Thomas Barnett isn't posturing about Iraq; he's thinking:
In the end, no one wants partition but the Kurds, hence my call for the 2K solution: draw down and pull back in southern Iraq and move bulk of forces to Kurdistan (where we are small) and Kuwait (where we are already large) and simply wait out the Sunni-Shia fight, which our generals on the ground don't want because they'd view that path as their operational failure. But frankly, political requirements (i.e., protecting our public's willingness to stay militarily engaged in the region) should overrule that professional desire. Political leaders don't tell generals how to fight, but they should--in our system--tell them when our fight has logically concluded.
By releasing the Sunni-Shia dogs of war, we force Saudi Arabia and Iran to fish or cut bait. Whatever they choose, we save our troops' lives and our political will to remain engaged.
To have unleashed this conflict and then stay to try to put it in slow-motion seems to me the worst of al worlds. Barnett has a point.