ANALYSIS/OPINION:

President Trump arrived in the Arabian desert hoping to realign the politics of the Middle East in the aftermath of a failed Obama policy. For eight years, President Obama tilted in the direction of Iran, believing that the influence of the Shia could balance Sunni dominance. The so-called nuclear deal with Iran was a geopolitical manifestation of this policy perspective. To put it simply, the policy didn’t work. In fact, it led to the widespread belief that the United States tacitly endorsed the Shia crescent or the imperial Iranian design.

President Trump hinted that this has to be corrected. With his May 21 speech, there is no doubt the United States will push back on previous policy and offer Saudi Arabia and other regional Sunni partners a reliable counterweight to Iranian ambitions.

In previous documents produced by the London Center for Policy Research, a Gulf States Red Sea Treaty Organization was proposed. Mr. Trump has called it an Arab NATO. As the president noted in his speech, the nations in the region have a primary responsibility to attack terrorism and the state sponsors of terrorism. He noted perspicaciously that the United States would not invest major troop deployments for this mission, but the U.S. will engage with its allies in logistical support, sophisticated arms, special forces when necessary, and intelligence on enemy movements and strategy.

More than anything else, the president offered assurance that the U.S. stands behind its allies. When, during the Obama presidency, President Abdel Fattah el-Sissi noted that “I love America, but America doesn’t love me,” he meant the United States was an unreliable ally that makes promises but doesn’t follow through. Specifically, he made reference to the Apache helicopters promised to Egypt but undelivered.

While presidential visits of this kind are invariably accompanied by hyperbole, this mission was indeed historic since it has already instilled in Saudi Arabia and Egypt confidence-building measures missing from erstwhile diplomatic conversations.

Some critics contend this Middle East gambit was designed to offset the political troubles dogging the Trump team in Washington, D.C. However, the trip was arranged well before the press powder keg exploded. From the outset of his presidency, Mr. Trump vowed to reset the global war against terrorism. He also wanted to alter a perception he is intolerant of Islam.

Clearly, there is a lot of work to be accomplished between announcements and an actual defense condominium. At this stage, inflated expectations have to face the bright light of regional realism. After all, there was a Middle East defense pact (CENTO) organized by President Dwight Eisenhower that lacked muscle and influence and, eventually, evanesced. There is also the Russian alliance with Iran and Hezbollah that could put a monkey wrench in Sunni planning.

A Sunni pact has as its target the Iranian influence in the Levant. But there are other goals as well. It is the Trump administration belief that Russia can be peeled from the alliance with Hezbollah and Iran. After all, why should Russian policy be determined, in large part, by Iranian imperial ambitions? Should this gambit be successful, Iran will be isolated and far more amenable to negotiation.

What the Trump visit to Saudi Arabia has done is open the region to a variety of options ignored by the Obama team. For eight years, the Sunni states lived with apprehension. Shia goals would be realized with a complicitous United States cheering in the background. That view — true or not — has been interred. Clearly, good will is not policy. It remains to be seen how the alliance plan can be realized. However, Mr. Trump’s visit was a symbolic triumph.

It is instructive that King Salman of Saudi Arabia greeted President Trump at the Riyadh airport, a gesture he did not extend to Mr. Obama. At this time, hope springs eternal. In a modest way, American leadership has been restored — at least for the time being. Now the pressure is on to translate the blaring trumpets and booming cannons of a state visit into policies that are sustainable and yield regional stability.

• Herbert London is president of the London Center for Policy Research and senior fellow at the Manhattan Institute.