David Warren of the Ottawa Citizen is a bracing columnist. An excerpt from Tribalism & Us:

Here is the paradox: that we cannot afford to abandon Iraq, for the very reason that things are so bad there. Were the Americans and allies to step out now, it would certainly become the staging area for both Shia and Sunni violence on a larger scale -- directed not only inward against each other, but outward across the Middle East, and given the huge Muslim diaspora now spread through Europe and North America, beyond.

Bear in mind, further, that Islamist terrorism against the West, feeds not only on Western weakness of will, but on this Muslim internecine strife. The most practical argument of the Islamists, to all their co-religionists, being: "We could unify ourselves if we all agreed to attack the West. We might even be able to destroy the West, because it has no idea how to defend itself."

It follows from this that a secret hope, not quite expressed in print (though sometimes expressed in the blogosphere), is vain. This is the hope that if Muslim fanatics are left to get on with killing each other, they will leave us alone. Like so many glib ideas, it sounds so plausible, but is the exact opposite of the truth.

An argument to back this claim up follows, but I don't quite understand it. However, I think Warren is partly right. That we have stirred up a Sunni-Shia split within the Muslim world could be to our advantage geostrategically. But it serves our interests best-- and is preferable for humanitarian reasons, too, of course-- that it be a cold war rather than a hot war. It's a good thing that Saudi Arabia (the great conservative money-power of the Sunni bloc) is hosting talks between Hamas and Abbas with a view (maybe) to Israel-Palestine peace, and trying to topple Ahmadinejad through an oil price war (which also gets up cheap gas at the pumps). But bloody sectarian warfare will leave behind a minefield of angry passions which can feed into future radicalism and terrorism.

The justification for the surge is that it might be able to stop the killing.

UPDATE: Fred Kaplan, long-time victim of Bush Derangement Syndrome, writes:

[I]n the unlikely event that the Bush administration succeeds in splitting the region along this sectarian divide, it will only harden tensions, inflame passions, and, by the way, do nothing to solve our immediate problems in Iraq.

This is why the Saudis and the Iranians are exploring common interests and seeking to mediate agreements—because the Americans, who used to do this sort of thing, have abdicated the role.

Wow, that's dumb. The Americans used to play the role of mediating agreements... with Iran?