BASRA….Why has Basra suddenly turned into a war zone? Was there some provocation from Muqtada al-Sadr’s forces recently? Or from rogue elements? Or what?

Probably neither. The New York Times reports that Iraqi government officials have been “signaling for weeks” that an offensive against the Sadrists was coming, and British officials told the Guardian that the operation was “carefully planned by Iraqi generals and the Baghdad government.” If this is true, it means that the ISCI-dominated government of Prime Minister Nouri al-Maliki has been planning a final assault on its Sadrist rivals for some time. Eric Martin speculates a bit:

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.

So why are we supporting ISCI in this internal battle against their political rivals? Spencer Ackerman:

As long as Maliki is in the prime minister’s chair, and as long as we proclaim the Iraqi government he leads to be legitimate, Maliki effectively holds us hostage. “I need to go after Sadr,” Maliki says. “The situation is unacceptable! In Basra, he threatens to take control of the ports, and in Baghdad, he’s throwing my men out of their checkpoints. Would you allow the Bloods or the Crips to take over half of Los Angeles?” And as soon as he says that, we’re trapped. It simply is not tenable for Petraeus to refuse a request for security assistance from the Prime Minister to deal with a radical militia.

Now, some Iraq-watcher friends of mine point out that this is absurd. “Sadr is, of course, a thug,” they say, “but he’s a nationalist. And he’s far less beholden to Iran than the Islamic Supreme Council of Iraq or Maliki’s Da’wa Party — both of whom we’re supporting! And most importantly, Sadr remains perhaps the most popular figure in Shiite Iraq. Petraeus can do business with him. This doesn’t make any sense!” And they’re right. It doesn’t. But as long as we sponsor the Iraqi political process — and a Sadrist doesn’t actually become premier himself — this will keep happening.

Plus there’s the fact that ISCI will let us build permanent bases in Iraq while the Sadrists would almost certainly kick us out if they came to power. We can’t have that, so ISCI it is. Whether their “carefully planned” operation will be any more successful at annihilating the Sadrists than any of their previous efforts remains to be seen.

UPDATE: More here from Joe Klein.