The New York Times reports:

In a classroom in Sadr City, the bustling neighborhood of the Shiite poor, dozens of men in white shirts and black pants received the most basic of Islamic religious instruction: how to wash before praying.

“After you wash your left hand, you must be sure to avoid any water drops on the right hand,” declared the instructor.

The men, once members of the Mahdi Army, the militia of the radical Shiite cleric Moktada al-Sadr, fought the Americans in the first years of the occupation and say they will again if Mr. Sadr gives the order. But for now they have come to wage a different battle in the ranks of the Mumahidoon, the successor to the Mahdi Army that, besides offering its members lessons in the Koran, organizes soccer teams, provides circumcision for the babies of poor families, picks up trash after religious pilgrimages and teaches computer literacy.

On the eve of what is likely to be a nearly complete withdrawal of United States forces from Iraq, one of the great questions is what Mr. Sadr is going to do. The Mumahidoon is one possible direction.

Created after Mr. Sadr disbanded the Mahdi Army in 2008, it is a lesser-known spoke of an Islamist movement that, like Hezbollah in Lebanon and Hamas in Gaza and in the West Bank, has used political, military and social arms — with financial support from Iran — to galvanize a Shiite underclass and stake out a prominent role in public life.

But Mr. Sadr also seems to be trying out several other roles, including street provocateur and vocal resister of American influence. The direction he decides on will determine in great part the immediate future of the country as the American military role diminishes.