U.S. Secretary of State John F. Kerry looks out from a helicopter over Baghdad on Wednesday. (Brendan Smialowski/Associated Press)

The Obama administration’s effort to win Arab allies in the fight against the Islamic State will have to overcome years of accumulated mistrust of American policies as well as the overlapping regional rivalries that helped fuel the ascent of the militants.

Progress has been encouraging. Arab states have scrambled to set aside differences to rally against the threat posed by the extremists, whose rampage through Iraq and Syria has unnerved rulers across the region.

On Thursday, Secretary of State John F. Kerry was to attend a meeting in Saudi Arabia with all of the major players in the Middle East, including the host country, Qatar, Egypt, Jordan, the United Arab Emirates and Turkey, to discuss ways to address the crisis.

Many of these countries are at odds over a range of issues and might not have been willing to send representatives to meet in the same room were it not for their urgent recognition of the new menace in their midst.

In common with their fear of the Islamic State, however, the region’s leaders also share a deep mistrust of the Obama administration, rooted in the past three years of increasing disengagement from the Middle East as the United States has sought to distance itself from the turmoil engendered by the Arab Spring revolts.

President Obama outlined a four-step plan on combating the threat of the Islamic State. Here are the highlights from his speech. (Nicki DeMarco and Ashleigh Joplin/The Washington Post)

President Obama, in a televised speech Wednesday night detailing his strategy for confronting the Islamic State, stressed U.S. support for the new Iraqi government’s effort to promote unity and enlisting Arab partners’ help to mobilize Sunni communities in Iraq and Syria against the group.

But already there is a disinclination to believe his promises, said Mustafa Alani of the Gulf Research Center in Dubai.

“We have reached a low point of trust in this administration,” he said. “We think in a time of crisis Mr. Obama will walk away from everyone if it means saving his own skin.”

Different countries are suspicious of the United States for different reasons, but all feel betrayed in some way by recent U.S. policies, said Salman Shaikh of the Brookings Doha Institute in Qatar.

“They see the security threat posed by the Islamic State. They want it defeated, because at the end of the day, the Islamic State overturns states, and as states, they are threatened,” he said.

However, he said, “there’s this nagging doubt that this strategy is intended just to serve American interests and not the broader interests of the region.”

Most Arab states see the Obama administration as having created the conditions that enabled the Islamic State to thrive by not being more helpful to moderates in Syria and by continuing to back Nouri al-Maliki as prime minister in Iraq — long after it became clear that he was pursuing policies that were alienating the country’s Sunni minority.

Driving the concerns is the memory of Obama’s turnabout on Syria a year ago, when the White House did not follow through on a threat to bomb Syrian President Bashar al-Assad’s regime in response to its alleged use of chemical weapons. Obama instead struck a deal with the Assad government to dismantle its chemical arsenal.

The reversal was the culmination of a series of disappointments for Arab supporters of the Syrian rebels who felt that the Obama administration had not kept its promises to aid the anti-Assad opposition. Obama has already said that existing plans to empower the Syrian rebels will be implemented as part of the new strategy against the Islamic State.

But, asked Jamal Khashoggi, an influential Saudi journalist who runs Al Arab TV channel: “What guarantees do we have that what happened a year ago won’t be repeated again?”

“To destroy the Islamic State you have to fix Syria,” he said. “You have to look at the reasons that created the Islamic State. This is a huge task.”

The tacit alliance that has emerged in Iraq between the United States and Iran is further stirring unease that the new strategy will only further empower Iran and its Shiite allies at the expense of Sunni influence in the region. The example of the town of Amerli, where U.S. airstrikes helped Iranian-backed Shiite militias rescue the Shiite Turkmen town from a siege by the Islamic State, illustrated the ways in which the focus on defeating the Islamic State risks reinforcing Iranian influence, Alani said.

Although Saudi Arabia and other Persian Gulf states have cautiously welcomed the replacement of Maliki — Haider al-Abadi, a member of Maliki’s Dawa Party, was confirmed as the new prime minister this week — they have seen no evidence yet that the change is anything more “than a change in faces,” Alani said

To Saudi Arabia and its gulf allies, the threat posed by Iran is at least as potent as that of the Islamic State, said Imad al-Salamey, a professor of political science at Lebanese American University in Beirut.

“In a strategic sense, the Islamic State does not pose a strategic threat to the gulf states the way Iran does,” he said, pointing to Arab concerns about expanding Iranian influence elsewhere in the region, including in Yemen, Lebanon and Bahrain.

Meanwhile, the Arabs themselves are divided. Saudi Arabia, Egypt and the United Arab Emirates are waging a struggle with Qatar and Turkey for influence in the aftermath of the Arab Spring uprisings. The feud recently resulted in airstrikes by the UAE and Egypt against Islamist militias in Libya. But it could be exacerbated anew by the struggle to lure Sunnis in Iraq and Syria away from the clutches of the Islamic State.

The countries’ competition for influence is responsible to a large degree for the fracturing of Syria, which helped facilitate the rise of the Islamic State, Khashoggi said.

“They have their own serious differences, which are probably to blame for this crisis we have,” he said. “Now they will meet to agree to confront the Islamic State. But can they do it and set aside their own agendas? This is to be seen.”