An Iraqi girl, whose family fled Ramadi after it was seized by Islamic State militants, stands outside a tent at a camp for displaced families on Monday. (Ahmad Al-Rubaye/Agence France-Presse via Getty Images)

IT HAS been apparent for some time that the United States lacks a strategy to fulfill President Obama’s pledge to “degrade and ultimately destroy” the Islamic State since it has no plan to root out the terrorists’ base in Syria. There was hope, though, that Mr. Obama’s half-measures might be enough to blunt the Islamic State’s advances in Iraq, leaving the Syria problem for the next U.S. president. With the stunning fall of Ramadi on Sunday, even that modest optimism is questionable.

“ISIL is on the defensive, and ISIL is going to lose,” Mr. Obama declared on Feb. 11, using an acronym for the Islamic State. “We’ve seen reports of sinking morale among ISIL fighters as they realize the futility of their cause.” The Iraqi army’s capture of Tikrit the following month seemed to provide confirmation.

But U.S. airstrikes late last week proved powerless to block a sophisticated Islamic State offensive to capture Ramadi, the capital of Anbar province 80 miles west of Baghdad. Once again, the Islamist terrorists are slaughtering captives and sending civilians fleeing in fear. Once again, they have seized U.S. military equipment, including about 30 vehicles the government sent into Ramadi the day before its fall. Once again, in the absence of more intensive help from the United States, the Iraqi government is turning to Shiite militia and the Iranian armed forces that support them. Iran’s defense minister, Brig. Gen. Hossein Dehqan, flew into Baghdad on Monday.

The Shiite militia cannot save Iraq, as its Shiite prime minister, Haider al-Abadi, well understands. Anbar is Iraq’s Sunni heartland, and many of its residents will regard the militia with as much or more fear than they feel for the Sunni extremists of the Islamic State. But Mr. Obama will not permit U.S. trainers to work with Iraqi forces on the ground or send U.S. spotters to make airstrikes more useful. Referring to U.S. aid, an Iraqi defense spokesman, Naseer Nori, told the Wall Street Journal, “Is it the role we wish for, is it to the strategic level we wish? Absolutely not.”

Beginning almost a year ago, the Islamic State carved out, across large swaths of Iraq and Syria, a terrorist state of sorts that Mr. Obama deemed intolerable. He said in September that it is a threat to “the broader Middle East,” including U.S. citizens and facilities, and “if left unchecked . . . could pose a growing threat beyond that region, including to the United States.” Yet he refuses to commit the Special Forces and military assistance that could meet that threat, portraying any alternative to his minimalist policy as being “dragged back into another prolonged ground war.” In fact, Sunni allies in the region will be reluctant to work with the United States until it has a Syria policy, and Sunni tribes in Iraq will not confront the Islamic State unless they believe the United States will stand by them. Every conflict will have ups and downs, as administration spokesmen said Monday. But it is Mr. Obama’s unwillingness to match means to strategy that threatens to prolong this war.

The Islamic State now controls Ramadi, a major city in Iraq. Here's why that matters and what to expect next. (Alice Li/The Washington Post)