Here's a long, but interesting analysis. Doom mongers, and the Defeatocrats will hate it:

The great question in deciding whether to keep fighting in Iraq is not about the morality and self-interest of supporting a struggling democracy that is also one of the most important countries in the world. The question is whether the war is winnable and whether we can help the winning of it. The answer is made much easier by the fact that three and a half years after the start of the insurgency, most of the big questions in Iraq have been resolved. Moreover, they have been resolved in ways that are mostly towards the positive end of the range of outcomes imagined at the start of the project. The country is whole. It has embraced the ballot box. It has created a fair and popular constitution. It has avoided all-out civil war. It has not been taken over by Iran. It has put an end to Kurdish and marsh Arab genocide, and anti-Shia apartheid. It has rejected mass revenge against the Sunnis. As shown in the great national votes of 2005 and the noisy celebrations of the Iraq football team's success in July, Iraq survived the Saddam Hussein era with a sense of national unity; even the Kurds—whose reluctant commitment to autonomy rather than full independence is in no danger of changing—celebrated. Iraq's condition has not caused a sectarian apocalypse across the region. The country has ceased to be a threat to the world or its region. The only neighbours threatened by its status today are the leaders in Damascus, Riyadh and Tehran.

Just the leaders we want to be threatened. And ultimately, removed.

That's the second source in as many days that I've seen claim that Sadr effectively flipped to our side (or, more accurately, refocused his efforts on insurgents with pretty much no concern for collateral damage to Sunnis) after getting whipped a couple of years ago. In addition, this piece portrays him as a nationalist, compared to SCIRI's Iranian ties.

I'm just not sure that I buy that. If it were true, it would be a nearly-complete reversal of conventional wisdom. While that itself is not out of the question--history has seen far crazier events take place--the evidence that has been compiled thus far, including the clear logistic support from Iran, and the fact that Sadr keeps running to Iran every time the going gets rough, really strongly points against this.

I'm willing to be convinced--heck, if it turns out that Sadr flipped after we smacked him down the first time, and has since then been overzealously hunting AQ and Baathists while trying to keep Iran from taking over his force, then it would be quite the story. But I'm going to need a lot more hard evidence that this is, indeed, the case, before accepting it.

I'm just not sure that I buy that.

No kidding. In reality, Sadr is more deeply anti-American than either Saddam Hussein or Mahmoud Ahmadinejad. But it is true that he is the most successful Iraqi leader, and that he is more nationalist and less pro-Iranian than SCIRI. SCIRI has always been Iran's favorite, and the US has also chosen it as an ally of convenience, so if you put that together you get a mutual interest of the US and Iran in Iraq. It's a desperate reality, because SCIRI is also terrible, just not as terrible as Sadr.

Postings like this one look more and more like a death spiral of gullibility. The big questions in Iraq have been resolved! Kill the planet by driving a Prius! Extreme longevity! You know, even bloggers get old. You can post and post and post about all of the things that you would like to believe. If you are lucky, then you can die in your sleep in your 80s like a lot of people do, believing until your last day that you are right on all of the big issues, including that you'll live to see The Singularity.

"But it is true that he is the most successful Iraqi leader, and that he is more nationalist and less pro-Iranian than SCIRI."

I wouldn't put my name to a statement like that either. If he is so successful, Why does he run away? If he is more nationalistic, why does he run away to Iran? Enjoy that petard.

"You know, even bloggers get old"
So do anonymous commenters.

All this was true in Vietnam in 71