According to Anthony Shadid and Sewell Chan writing for the Washington Post, the Sunday, April 4, 2004, Shiite Muslim uprising in Iraq, with "mass demonstrations and attacks in Baghdad and southern Iraq, [led by the young, militant cleric Moqtada al-Sadr with his Mehdi Army] ... has realized the greatest fear of the U.S.-led administration since the occupation of [Iraq]] began." . "The unrest Sunday followed a series of calibrated moves by each side that appeared to be designed to test the resolve of the other.