A cease-fire critical to the improved security situation in Iraq appeared to unravel in the strategic southern port city of Basra, where Shi'a cleric Muqtada al Sadr's Mahdi Army fought fierce gun battles with Iraqi security forces that are trying to bring the city under government control. The Iraqi government has undertaken an operation targeting six districts in central and northern Basra where the Mahdi Army militia of al-Sadr has a strong presence. The operation was launched after...