U.S.-backed Iraqi forces­ are struggling to make headway in their battle to retake the western city of Ramadi, highlighting shortcomings in Washington’s strategy to counter Islamic State militants.

Three months after the city’s fall, Iraqi forces­ have not yet surrounded the city 80 miles west of Baghdad, commanders say, the first stated aim of the counter­offensive.

The stuttering pace of the operation is likely to dent the image of the United States in Iraq, even as it spends $1.6 billion on training and equipping Iraqi forces. […]