The evening news keeps referring to the escalating violence of "the insurgency" in Iraq.
The insurgency? Which one? Shiites? Sunnis? Baathists? Foreigners? Iranian agents? Al-Qaeda, Zarqawi, Muqtada? How can you try to quell violence when you don't know who's responsible or what their goals are? Stopping a bunch of radical vigilantes takes a different strategy than trying to stop a militia made of ex-veterans. Steve Gilliard talks about this problem all the time.
If there are a whole bunch of factions shooting things up when Americans leave, there will be civil war or genocide or both before the decade is out. The only way to prevent this would have been to establish national security before the violence had broken out. Otherwise radical, violent groups will galvanize more moderate groups into adopting violence in self-defense. Obviously, it's a little too late for that now. Now you need to provide a big force to do peacekeeping, and you need to identify all the principals, something the occupation forces seem to be unable to do.
The big question from the American point of view is whether they will wait for American withdrawal before tearing into each other, leaving the American forces in the middle or they will all work together, wittingly or unwittingly, to drive out the Americans before going at it. Both scenarios are bad news for American troops. Both scenarios are even worse news for Iraqi civilians.
Brad DeLong provides us with David Hume:
In reality, there is not a more terrible event than a total dissolution of government, which gives liberty to the multitude, and makes the determination or choice of a new establishment depend upon a number, which nearly approaches to that of the body of the people: for it never comes entirely to the whole body of them.
--Melissa O, at 18:45