Iraq’s prime minister has told Shiite militiamen to surrender their arms or face an all-out assault by U.S.-backed Iraqi forces, senior Iraqi officials said Wednesday, as President Bush said he will commit an additional 21,500 American combat troops to the war. Under pressure from the U.S., Prime Minister Nouri al-Maliki has agreed to crack down on fighters controlled by his most powerful political ally, Muqtada al-Sadr, a radical Shiite cleric, according to officials. Previously, al-Maliki had resisted the move. Full Story