The fall of Ramadi to the Islamic State has raised new questions about the Obama administration’s Iraq strategy, including its efforts to resurrect Iraqi security forces and the focus of U.S. and Iraqi attention on retaking the city of Mosul by the end of this year.

President Obama was briefed on the latest developments during a National Security Council meeting Tuesday, according to a White House statement, although officials said no formal strategy review is underway.

White House press secretary Josh Earnest said that the fall of Ramadi was undoubtedly a “setback” but stressed “how important it is for us to maintain some perspective on this.” He cited successes such as the defeat of militants last month in Tikrit and Saturday’s raid by U.S. Special Operations forces that killed a senior Islamic State operative in Syria.

But the hasty retreat this week of the Iraqi army from the capital of Anbar province, the country’s largest and the heartland of its Sunni minority, clearly stunned an administration that has argued it is making steady progress toward Obama’s goal of debilitating and defeating the Islamic State.

U.S. officials insisted that their strategy of bolstering Iraqi forces and aiding them from the air remained sound. “But that doesn’t mean you can’t look at better ways to implement it,” said a defense official.

The White House statement said Obama “reaffirmed the strong U.S. support” for Iraqi Prime Minister Haider al-Abadi and praised Tuesday’s decision by the Iraqi Council of Ministers “to accelerate the training and equipping of local tribes in coordination with Anbar authorities, expand recruitment into the Iraqi Army, train local police, and develop a consolidated plan to retake Ramadi.”

Details emerging from Ramadi and U.S. assessments of events there indicated that security forces who had held out against embedded Islamic State fighters for more than a year departed en masse after a coordinated series of devastating suicide bombings late last week and over the weekend.

The ability of U.S. and coalition aircraft to attack militant forces was hampered not only by a weekend sandstorm, but also by the lack of on-the-ground spotters to direct air attacks into the heavily urbanized area.

In accounts and reactions pieced together from a number of U.S. officials, who spoke on the condition of anonymity because they were not authorized to discuss the issue with the news media, the precipitous exit began when Iraqi forces, while greatly outnumbering the militants, were shaken by the scale of the explosions, which took out entire city blocks, and the casualties they caused, including the deaths of senior commanders and at least an entire unit of Iraqi special operations troops.

As the Islamic State consolidated its control Tuesday, blame was distributed in many directions. Senior military leaders expressed disappointment at the manner in which Iraqi government forces withdrew and questioned their leadership.

Sheik Abdalrazzaq al-Sulayman, a leader of the Dulaim tribe in Anbar, said during a visit to Washington that Ramadi fell because the Abadi government had failed to properly support Sunni tribesmen in the province.

Sulayman warned of a “negative reaction” among Sunnis if Shiite militiamen press into Anbar, as Abadi has now ordered, and urged the United States to begin supplying weapons to tribesmen.

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)

Others said that even the government troops in Ramadi had not been adequately armed. “We have to be realistic here,” said Ahmed Ali, a senior fellow at the Education for Peace in Iraq Center. “There has been a delay in supplying ammunition to Iraqi forces in Ramadi, which weakened their morale.”

House Speaker John A. Boehner (R-Ohio) pointed the finger at Obama, who he said was “not taking this threat as seriously as [he] should. When a major city in Iraq, Ramadi, gets overrun by ISIL and the administration says, ‘Well, it’s just a temporary setback’ — it’s 70 miles from Baghdad.” ISIL is an alternative term for the Islamic State.

The most immediate concern, administration officials said, is to come up with a plan to retake the city.

Any such plan is likely to require a stepped-up focus on Anbar at the expense of planning to retake the northwest city of Mosul, Iraq’s second largest and both the symbolic and actual center of the Islamic State’s power in the country. Mosul fell to the militants in June after the wholesale desertion of Iraqi security forces.

The U.S. military has described control of Anbar as necessary to shape a successful offensive in Mosul by retrained and rearmed Iraqi forces aided by U.S. airstrikes. But routes into the city are closed, and there is widespread agreement that the Iraqi military is not yet prepared for the major urban combat that would be required.

U.S. military officials linked the performance of Iraqi security forces in Ramadi not to the overall strategy but to what they see as poor management of those forces.

“At the broader level, this has to be about the Iraqis leading the fight,” one senior U.S. military official said. “The U.S. leading the fight will not be an enduring solution.”

Pentagon and military leaders agree that Anbar is important on the way to Mosul. The U.S. military has begun efforts to train thousands of Sunni tribal fighters at a base in the western Anbar desert and to streamline weapons supplies to them through the Shiite-led government in Baghdad.

But State Department and other senior administration officials argue that while the United States cannot fight the Iraqi military’s battles, it can and must redirect its primary strategy away from Mosul and focus it fully on Anbar. If Anbar is lost, they have argued in months of debate with the Pentagon, there is little point in planning for Mosul.

U.S. mobilization of the Anbar tribes was key to quelling al-Qaeda militants in Iraq in 2007, but plans to establish them as a permanent part of the Iraqi security forces were thwarted by then-Prime Minister Nouri al-Maliki, who cut them off in favor of the Shiite-dominated national military.

The militants were the precursor of the Islamic State, which returned to Anbar to tell the tribes that Baghdad will only betray them again. The task of the United States and the Abadi government has been to convince them that this time will be different.

That effort was undercut when Iranian-backed Shiite militia forces joined the Iraqi army’s fight to drive the Islamic State out of Tikrit and other areas in eastern and central Iraq this year. Tribal leader Sulayman said that Shiite paramilitary units had already turned back residents fleeing the Islamic State in Ramadi and were stoking sectarian tensions.

Despite ongoing concerns about the Iraqi military and the militias, circumstances are so dire in Ramadi that the Anbar provincial council — which had insisted that Abadi not allow the Shiite fighters into the province — has asked for their help.