The blood of two militants killed during Islamic State’s rout in the Iraqi town of Jalawla has yet to be washed away, but a turf war is already brewing between Kurdish and Shi’ite forces that jointly drove the insurgents out.

The recapture of disputed territory and towns such as Jalawla is reopening rivalries over the boundary between areas of Kurdish control and those administered by the Shi’ite-led Baghdad government.

Local Sunni Arabs displaced in the fighting have little choice but to align themselves with one side or the other. […]