The violence in Iraq has dramatically escalated over the past several days, as the government of Prime Minister Nouri al-Maliki has apparently instituted a major operation in the city of Basra in an apparent effort to bring the city under control. The offensive continues into the second day, as Iraqi security forces have cordoned off the city and are apparently going from block to block clearing it of Shiite militia fighters. The operation is unusual in that it appears to be the first large-scale operation undertaken almost entirely by Iraqi forces, with little American or British support. Basra has been the scene of protracted conflict between competing Shiite militias, Moqtada al-Sadr's Mahdi Army and the Badr brigade, the paramilitary wing of the Supreme Islamic Iraqi Council (SIIC, formerly SCIRI) the dominant Shiite party in al-Maliki's ruling coalition. Al-Maliki claims the operation is aimed at all rogue Shiite militiamen in Basra and has ordered them to surrender their arms in 72 hours or face further action, but members of Badr brigade and SIIC hold senior government positions throughout central and southern Iraq, and so the offensive appears to be aimed largely at Sadr's Mahdi Army. Or at least the Mahdi Army thinks so, as members have taken to the streets of Basra to fight government forces and Sadr himself has called for a campaign of civil disobedience that will apparently be enforced by his followers at gunpoint. Worse yet, members of the Mahdi Army have responded to the attacks in Basra by taking to the streets of Sadr City in Baghdad, clashing with American forces and launching mortar and rocket attacks against the Green Zone. Hardliners in the Mahdi Army have been impatient with Sadr's cease-fire with American and Iraqi forces, and had already recently been clamoring to end the case-fire in the wake of Iraqi government attacks on the Mahdi Army and arrests of Sadrist leaders which may have been undertaken to weaken Sadr against his foes in SIIC in upcoming provincial elections. An aide to Sadr states that the cease-fire is still in effect, and Sadr presumably has little interest in resuming the open conflict of 2003 and 2004, but it's hard to know what that really means with Mahdi Army fighters in the streets actively attacking American and Iraqi forces and attempting to assert control over Sadr City and Basra.
UPDATE: Recommended reading from Anthony Coredesman, who explains that the conflict in Basra and now Baghdad is more a sign of increased Shiite vs. Shiite violance, and less about the national government asserting its authority. And here's Spencer Ackerman on why backing al-Maliki and the Shiite parties he represents is not necessarily in our best interests.
UPDATE II: As I note above, a few commentators think that this offensive is about the efforts of the SIIC and Dawa-dominated national government to diminish Sadr's growing influence in southern Iraq in advance of upcoming elections. However, if you look around you can also find speculation that this offensive is more about the national government's efforts to destroy a weakened Sadr and his Mahdi Army. This does not seem plausible to me. In fact, it appears to me that some commentators have mistaken Sadr's relative quiet this past year as a sign that his power is diminishing. But I think it's more likely the opposite. Sadr reportedly called the cease-fire against the U.S. to consolidate his movement, and also to avoid unnecessary conflict that only threatened to result in the death or arrest of his fighters and leadership. But the Mahdi Army has hardly been engaged in a cease-fire in the south, where Shiite conflict has been protracted and where he is apparently consolidating his power. That doesn't square with the idea that this offensive is all about finishing off a weak Sadr. From our perspective here of course it's impossible to know what's really going on, but reading the more astute Iraq commentators it seems clear that this is only another phase in the conflict between the Shiite parties in Iraq and it is not at all clear who will be the eventual victor.
UPDATE III: Here's Eric Martin on why we're backing Maliki over Sadr, but why that might be backing the wrong horse.
UPDATE IV: Via Marc Lynch, Reider Vassar suggests that the fighting in Basra is not so much about provincial elections as it is about al-Maliki consolidating his power base in the Iraqi government. But a significant player in Basra-the Fadila party-goes largely unmentioned in reports of the fighting, and Vassar suggests that we cannot know what's truly going on until we know where Fadila stands.
UPDATE V: The Mahdi Army has apparently locked down Sadr City, in anticipation of incursions by Iraqi and U.S. forces which have surrounded this portion of Baghdad but have thus far not ventured in.