Ahmad Al-Rubaye / AFP-Getty Images
Iraqi men work to extinguish a blaze said to have been caused by a
U.S. rocket attack in Sadr City on April 8, 2008

Why has Moqtada al-Sadr cancelled his planned “Million Person” march against the U.S. presence in Iraq? Anyone who sees it as a sign of declining tensions between the radical Shiite leader’s Mahdi army and the American and U.S. forces would be wrong.  Nor has al-Sadr’s decision to call off the April 9 protest done much to ease fears in a capital city that is still on the edge. The Iraqi government has ordered a curfew throughout Baghdad for Wednesday. Local residents hustled to buy bread and vegetables for what they fear could end up being an extended time indoors. In the Green Zone, the American Embassy told its staff to sleep in inside their large office building rather than risk rocket barrages in the flimsy trailers where they live.

Sadr’s protest plans are hardly new. The cleric calls annually for marches on April 9, the date in 2003 when U.S. troops drove into central Baghdad and the last vestiges of Saddam Hussein's regime dissolved. Typically, the demonstrations have had mixed success. They're always called with little time for preparation and have probably never reached a real million, in part because of active efforts to foil them. I remember walking in Firdos Square, where the Marines had yanked down the statue of Saddam, on the first anniversary in 2004. Sadr's Mahdi Army had just unleashed a violent uprising against American troops and was planning a march in the square. U.S. troops declared the area a closed "military zone," setting it off with barbed wire while a Humvee circled slowly, blaring heavy metal out of loudspeakers to the frustration of weary residents living along the route. Sadrists stayed away but their movement grew.

This time Sadr blamed interference as one of the reasons for canceling the demonstrations. In a statement Tuesday, he said government forces were blocking followers trying to get to Baghdad to join in. "The government is still under the occupation pressure and its deceiving policies, therefore it is trying to prevent the million-person annual demonstration," the statement read. He said he was calling off the march for the safety of his supporters. In fact, there have been three days of fighting in the stronghold of Sadr City and some of its entrances are blocked by wire and Iraqi security forces guard towers. He compared it to the way Saddam used to prevent movement. And, while calling off the march, he congratulated his supporters for their resistance: "Allah salutes your efforts, and jihad and resistance of the occupation who violated our lands and sanctities, killed our youth and elderly, bombed our cities and took over our territories." Late Tuesday, the government announced that the curfew would still allow for an anti-occupation rally in one square in Sadr City, providing a little relief valve--though the ban on vehicle movement will prevent many others from attending.

Sadr may be seeking to avoid, for now, clashes with security forces that would create the impression that his followers were at fault. Members of his Mahdi Army militia have just fought government forces to a draw in the southern port city of Basra. (The standoff prompted repeated questions from U.S. Senators grilling U.S. Ambassador to Iraq Ryan Crocker and Gen. David Petraeus in Washington on Tuesday.) But, as the cliché goes, Sadr knows he can win the battle and still lose the war. Each assertion of militia power also alienates conservative Shiite Muslims who look down on Sadr's movement as a power-crazed rabble. And the other Shiite parties in the government, led by Prime Minister Nuri al-Maliki, seem to be unified among themselves and in an alliance with powerful Kurdish factions in standing up to Sadr. That has opened the door for the Iraqi and U.S. military to press into militia areas and provoked the recent fighting in Baghdad, killing scores and causing hundreds to flee Sadr City for safer neighborhoods.

Sadr knows he is in a long-term power struggle with fellow Shiites even as Shiites in general crave unity. While those fighting against his militia wear government uniforms, they are largely loyal to rival Shiite parties in alliance with Maliki. It's as much about politics and power as it is about law and order. Maliki has made an unprecedented call for Sadr to disband the militia or risk having his movement disqualified from the local elections later this year. As things stand now, Sadr's partisans are expected to do well and the rival parties are expected to lose seats in those elections, which might take place by December.

The prospect of winning a sweep of southern governorships is a goal Sadr wants to preserve and he has to make sure his militia is not seen as the aggressor in an intra-Shiite war. Instead of just rejecting the call to disband the Mehdi Army (and no one who wants to be a player in Iraq wants to disband his militia), he said he would consult with high religious authorities who are backed by all the Shiites. Those consultations might go better for Sadr if the militia is not seen causing trouble in the streets. In the meantime, he threatens to end the general ceasefire he called for his militia to follow since August. So a pronouncement calling off the march will help him look like a peacemaker even if he's not ready to put down the guns.