Even as Iraqi special forces and Shia militias roll back the self-proclaimed Islamic State, Baghdad has done little to address the underlying causes of Sunni militancy.

The recent spate of bombings in Baghdad is testing the U.S. commitment to withdrawal, and Iraqi political leaders’ ability to maintain their grip on power, says expert Sam Parker.

Sam Parker, an expert on Iraq, says the initial results from the provincial elections indicate Prime Minister Nouri al-Maliki has been strengthened and Sunnis in restive Mosul may play a more positiv…