After only modest gains in the first few weeks of their drive to retake Anbar province, Iraqi government forces have given up hopes of swift advances against Islamic State militants.

The campaign, launched after the provincial capital Ramadi fell in May, initially aimed at recapturing the city quickly but then shifted east to break the militants’ 19-month grip on the city of Falluja and secure supply lines from Baghdad.

Confronted with Anbar’s sprawling terrain as well as the reality of a weakened fighting force, the sensitivity of sending Shi’ite militias into Sunni strongholds, and political tensions including an Iranian-Western fight for influence, Baghdad and its allies have had to modify expectations. […]