I'm trying to figure out why this NY Times article places stories of Iraqi Shiites turning against Mahdi Army elements within the "the surge is working!" narrative, especially given that reporter Sabrina Tavernise seems to understand that changes in the organization are the result of processes that predate the surge:

"The street militia of today bears little resemblance to the Mahdi Army of 2004, when Shiites following a cleric, Moktada al-Sadr, battled American soldiers in a burst of Shiite self-assertion. Then, fighters doubled as neighborhood helpers, bringing cooking gas and other necessities to needy families.

Now, three years later, many members have left violence behind, taking jobs in local and national government, while others have plunged into crime, dealing in cars and houses taken from dead or displaced victims of both sects.

Even the demographics have changed. Now, street fighters tend to be young teenagers from errant families, in part the result of American military success. Last fall, the military began an aggressive campaign of arresting senior commanders, leaving behind a power vacuum and directionless junior members."

Though you probably wouldn't know it from reading U.S. media, the Mahdi Army is actually the militia wing of Muqtada al-Sadr's larger movement, Jamaat al-Sadr al-Thani, ("the Association of the Second Sadr," in reference to Muqtada's father, Grand Ayatollah Sadeq al-Sadr) just as the Badr Brigade is the militia wing of the SIIC (formerly SCIRI). As with similar movements such as Hamas and Hezbollah, there is a lot of overlap between the wings, with the militia tending to attract more thuggish elements who latch on to the movement's legitimacy to facilitate their thuggery. It's been clear for a long time that Muqtada recognizes this as a problem, which is why he's continually disavowed renegade Mahdi Army factions, either dealing with them himself or, more often, allowing them to be dealt with by U.S. forces, as he has moved away from violence and toward politics. That these young gangsters are now being turned in by Shiites is not proof of American military success as much as it is of Muqtada having achieved many of his political goals, and his movement having achieved even greater legitimacy.