The purposes behind the continued targeting of the Sadrists are manifold. First, there has been an ongoing competition between the Sadrist current and the ISCI/Dawa factions for wealth, power and control of the Shiite political sphere. Against that backdrop, the looming October 1 regional elections have provided ISCI with an added sense of urgency: the Sadrist current is considerably more popular and stands to make a serious dent in ISCI's local political clout (ISCI is somewhat overrepresented locally due to the fact that the Sadrists boycotted the last round of regional elections in 2005).
That is why ISCI vetoed the most recent iteration of the regional elections law. It is likely that Cheney, on his most recent visit, promised US support for anti-Sadrist activities in return for ISCI's withdrawal of its objections. Along these lines, it is no accident that the strategically vital southern city of Basra is currently the site of the most concerted effort to purge the Sadrists. If ISCI can push the Sadrists out of Basra (the main port city, and transit hub of oil and other goods), losing ground in other Shiite localities would be less painful.
For the Bush administration, backing ISCI/Dawa is appealing for a few reasons. First, ISCI/Dawa are amenable to the US presence, whereas the Sadrist current is strongly opposed. So ensuring that ISCI maintains its political power is essential to the goals of maintaining permanent military bases and gaining preferential access to oil residing in the Shiite-dominated south. Ensuring the legitimacy of democratic process is, apparently, not quite as important.
Second, the US could be attempting to drive a wedge between Iran and its strongest allies in Iraq (ISCI/Dawa) by providing robust support against those factions' main rival (the Sadrists). I remain highly dubious as to the prospects of such a gambit, however, and find it quite plausible that ISCI/Dawa would view us as friends of convenience - useful on a limited, contingent basis - without completely abandoning their Iranian allies. For the Bush administration, even preserving the chance to secure permanent bases and access to oil might take the sting out of failing to cut Iran out of the picture completely, though.
Regardless of the stated objectives, the question of execution remains. Trying to weaken the Sadrist current is a lot easier said than done. For one, it is a movement made up of over 2 million Iraqis - represented by a fairly sizable bloc in the parliament and with a large base of support in Baghdad. Sadr's network delivers necessary social services to large segments of Iraq's society, and that ability, as well as his religious lineage and nationalist, anti-occupation rhetoric make him and his movement extremely popular.
The Mahdi Army militia, while rough around the edges and lightly armed, are highly motivated and determined. The early results of the most recent clashes vary depending on the source. While Maliki took to the airwaves today to issue an ultimatum to the Sadrists, it is unclear which faction is in a position to dictate terms. First Maliki:
Iraq's prime minister on Wednesday gave gunmen in the southern oil port of Basra three days to surrender their weapons and renounce violence as clashes between security forces and Shiite militia fighters erupted for a second day.
Sadiq al-Rikabi, a chief adviser to al-Maliki, said gunmen who fail to turn over their weapons to police stations in Basra by Friday will be targeted for arrest. He said they also must sign a pledge renouncing violence.
Juan Cole translates some pieces that suggest that Maliki's bargaining power is not quite strong enough to make such demands:
Al-Zaman reports in Arabic that members of the Islamic Supreme Council of Iraq (ISCI, formerly SCIRI, led by Abdul Aziz al-Hakim); the Da'wa Party led by Prime Minister Nuri al-Maliki; and the Badr Corps paramilitary of ISCI have fled their HQs in Basra and Kut, because of the threat that they will be stormed by Mahdi Army militiamen [seeking revenge for the current offensive], In fact, some such buildings already have been attacked. [...]
Al-Zaman says its sources in the Sadr Movement confirmed that the Mahdi Army has gained control of the main road between Amara and Basra, allowing it to cut the government troops off from military supplies.
Badger translates a piece that says US soldiers were employed to protect the ISCI's offices in Baghdad as well. Events such as these should make US policymakers wonder whether, yet again, we are backing the less popular local elements simply because they tell us what we want to hear.
Speaking of which, Sadr has another card to play, and so let me make another prediction: If the US and its putative Iraqi allies do not back off, the Sadrists will attempt to bring down the Maliki government by coordinating a no-confidence vote. While Sistani and others have fought to maintain a united Shiite political bloc for some time, alas, not even the cat herder can prevent this rift unless there is a let up in violence.The question remains: can the Sadrists pull in enough Shiite and Sunni lawmakers to back this play? I'd say the odds are better than 50/50.