Notice how Saturday's large and dramatic LAT front page photo frames Mahdi Army fighters (and, by way of the caption, "Muqtada Sadr") as gloating, oncoming, renegade antagonists to Prime Minister Maliki and the Iraqi government.
So the story line is set, although the factions aligned under the rubric of the Iraqi government (which are filled with like agents) actually instigated the hostilities. Emphasizing the fighters as "parading," the weaponry and the hoods/masks play on stereotypical gang associations (including what reads like an intentional hand gesture by the guy on the left) to frame the Mahdi as the "gansta-terrorists" in this fight.
Look for the Administration to vigorously cover-up the Iraqi Government's power play and (rhetorically, as well as literally) attempt to nail the Mahdi, although more for face-saving purposes than anything else. (It's an unfortunately thing, too, as the Mahdi cease-fire had been holding steady, with the faction apparently training its eye on the next round of elections.)
In a destabilizing assault that the U.S. wasn't informed of and never saw coming, another thing to watch for is the extent to which traditional media gets out in front in the visually enabling.
(image: Khaldoon Zubeir/Getty Images. Basra, Iraq. April 2008. via Los Angeles Times)