The always prodigious Brad Plumer takes on Iran:

Meanwhile, if … Khamenei’s really calling the shots here, this might mean that Iran’s more willing to deal with the United States on the foreign policy front than commonly thought—Khamenei may be a nasty fellow, but many, including Gasiorowski, don’t think he’s wholly irrational: “It seems likely that he will try to avoid a confrontation with the United States.” Then again, not everyone shares this view: Michael Ledeen, for instance, has tried to trace the al-Sadr uprising in Iraq back to Khamenei himself; there’s also the question of whether the Supreme Leader has any control over, say, the elements of the Revolutionary Guard that’s currently harboring al-Qaeda; or if he just prefers to look like he has no control over those elements, in order to maintain plausible deniability. Interesting times…

I don’t doubt Iran backed Sadr’s uprising. Intelligence and other sources of information can be bent, represented, and mis-represented in any numerous ways to prove or disprove it. But, it would not surprise me if Khamenei himself ordered/supported Sadr’s Mahdi Army to take up arms against the US in order to make Iraq’s conversion to an Iran-like Wilayat al-Faqih system the only possibility at the time. Iran’s conservative leadership has had a desire to export its form of governance upon the Middle East since the Revolution itself, which was one of the initial reasons Iran began supporting Hizbollah in Lebanon. Iraq offered Iran a pristine opportunity to create a twin state, but due to Sistani’s differing opinion on how the final government should look he broke with his Iranian benefactors and forced Sadr to stand down and pursue the political process. While Sadr did not directly enter into elections, his political gravitational pull does exist, especially in the south. But the SCIRI, Iran’s traditional Iraq-based lackies and Tehran’s most loyal proxy force in the country, is where the power truly resides. It has an electoral mandate and dibs on southern Iraq when, perhaps not if, the southern provinces become one confederated political unit. It’s difficult to say whether or not Tehran finds Iraqi federalism beneficial, but anything Sistani finds problematic will probably make Khamenei happy to a point. In the worst case scenario for Khamenei — that being a Baghdad controlled by a government not as friendly to Iran — the south would remain loyal and easily pliable, depending on how the developing rift between Badr’s Mahdi Army and the SCIRI is handled.

The move toward southern autonomy is especially important when placed in the broader context of Iran/Iraq cooperation since it suggests that the differences held between Jaafari’s Dawa party and Iran/SCIRI are becoming more pronounced and possibly exploitable. While Dawa does have links to Iran, they primarily came about during the Iran-Iraq war as a result of shared hatred for Hussein and not due to shared, identical ideologies. While Iran and the Dawa-headed Baghdad government are on extremely friendly terms, Khamenei and those around him feel more comfortable working with the SCIRI since it shares a similar view of Shi’ite rule. The SCIRI believes that the ulema, or the group of Islamic scholars, should serve as the basis of institutionalized Shi’ite law, while the Dawa party is more a fan of utilizing the umma, or the overall Islamic community, in the same context. Ulema is obviously more conducive to Iranian-style governance which, combined with the SCIRI’s near hegemony in southern Iraq, serves as the driving force behind Iran’s continued support for the party and its armed militia. That doesn’t mean Iranian support cannot shift back and forth between factions in the future, say from the SCIRI to Sadr’s Mahdi Army, in order to advance Tehran’s overall agenda. Due to that, it’s highly doubtful there is an overall, coordinated Iranian plan to completely destabilize Iraq by targeting Shi’ite leaders, regardless of faction or loyalty. If Tehran wants to play, it has to leave some cards on the table to work with depending on the flop.

As far as Iran’s Revolutionary Guard Corps (IRGC), it is a huge problem. Its very existence takes almost any logical belief one has about Iranian politics and foreign policy, especially, and throws it into chaos. I do not know the extent of IRGC/Supreme Leader coordination, but I do know that the central Iranian authority has rarely felt the need to clamp down on the IRGC’s controversial activities. Its leaders openly discussed tossing Khatami out during his final term, and now they’re backing Ahmadinejad with full fervor. While Ahmadinejad was a commander in the IRGC Quds Force, it’s doubtful he’s commanding the IRGC from the president’s office; it’s most likely the other way around. That could be good and bad, because with Ahmadinejad in office the Iranian political apparatus has lost that “plausible deniability” Brad mentioned. But it also allots the IRGC greater leverage in cracking down on domestic dissent.

Would the IRGC directly back Sunni insurgents in Iraq, as the administration is claiming currently? Stranger things have happened, and any cooperation could certainly be directed at US forces and not Shi’a; not to destabilize, but to push the US out so Iran can move the chess pieces around even more freely. The possibility of damage spill over to friendly Shi’a and Kurds still makes the USG’s claims extremely suspicious, but when it comes to the IRGC anything is possible.