To theU.S.military,Muqtadaal-Sadr,37,wasanuisance;toIraq'sSunniminority,heisanemesis.

Al-Sadr's Shi'ite militia, the Mahdi Army, is thought to have killed tens of thousands during the sectarian

warof2006-07.Nowtheayatullahintrainingwieldspoliticalpowerandmilitiamight:hisblocof

parliamentarians can make or break the Iraqi government.