Putting more U.S. soldiers in the streets of Baghdad risks a new showdown with a radical anti-American cleric who has modeled his movement after Lebanon’s Hezbollah guerrillas. Muqtada al-Sadr’s Mahdi Army has re-emerged as a key force in the majority Shiite community after suffering substantial losses during two uprisings against the U.S. military in 2004. Sunni Arabs believe the militia is responsible for kidnapping and killing thousands of Sunnis since the Feb. 22 bombing of a Shiite shrine. Full Story