Before Bush-43 invaded Iraq I knew of the potential religious differences there - because I knew that Iran was Shia, Arabia was Sunni, and Iraq was mixed. At the time I related the Sunni Shia split to the Catholic Protestant split (but didn't realize how wrong I was or how different it was). Shortly after the invasion I realized Iraq could split into three parts .
When Ayatollah Sistani was "making peace" I related him to a thirteenth century cardinal. This isn't far from accurate because Islam did most of its growth in the 700's. It's not terribly surprising that the thirty years war, between Catholics and Protestants, occured during the 1300's. Or that the hundred years war (Joan of Arc) occured shortly after.
Now the U.S. is casually threatening to pull out of Iraq. On this I take W almost entirely at his word. He'll start pulling after the 2008 presidential election and not one day before. At the same time, while Iran is back Iraqi Shiites, Arabia has voiced support for Iraqi Sunnis.
And it was shortly after W invaded that I saw Iraq could split into three countries. I likewise said that Basra / East Iraq will be allied with Iran and the Anbar / West Iraq will be allied with Arabia. But that the allian between Anbar and Arabia was more of self-defense rather than out of friendship.
I half-way view the situation as to what happened to Judea and Samaria durings their last centuries - where Egypt was south of Judea and Assyria and Babylon were north and east of Samaria.
The big trouble in Iraq is Baghdad. Baghdad is divided between a Shites and Sunnis. And a person from western Baghdad cannnot go into eastern Baghdad without needing fairly high security.
I've already spoken in favor of breaking Iraq apart. And if, with the downfall of Iraq, if Baghdad falls as well, so be it. I'm neither in favor of the dissolution of Baghdad nor opposed to it. But Baghdad is central to the troubles in Iraq right now. I think and I hope that there will be two cities - East Baghdad and West Baghdad - or whatever names the Arabs choose to give the cities.