A recent Islamic State offensive in Iraq’s Anbar province suggests that the extremist organization is changing tactics, relying less on local Sunni Muslim tribes for support and carrying out what one coalition strategist called a “counterinsurgency campaign” intended to undercut any U.S.-led effort to enlist tribes against it.

The outlines of this new strategy became apparent last week when the Islamic State launched an assault on Ramadi, the capital of Anbar province, without the assistance of local fighters. That assault was preceded by weeks of assassinations aimed at prominent members of Anbar tribes.

“This is the first real multi-pronged assault by the group acting on its own,” said Aymenn al Tamimi, a Middle East-based researcher who studies jihadist groups in Iraq and Syria, referring to the campaign, which began last Friday. […]