WASHINGTON — On his first official trip to the Middle East, President Donald Trump has resoundingly thrown America’s lot in with Sunni Arab states and cast Shiite Iran as a global pariah, even as Iranians re-elected a president who has offered to work with the West.

During his two days in Riyadh, Trump’s support for the autocratic monarchies in Saudi Arabia and other Gulf states, as well as his fierce denunciation of Iran, allowed him to claim a historic new coalition of interests.

In the next two days, in Jerusalem, he doubled down and argued that Israel and the Arabs should join forces against Iran and along the way, resolve Israel’s conflict with Palestinians in a grand bargain that has eluded diplomats for decades.

But as he departed for Rome on Tuesday, Trump had little to show beyond lofty rhetoric, symbolic visits and a shower of flattery from kings, potentates and a prime minister.

When it comes to the Middle East peace, the devil is in the details, and Trump refused to provide any during his visit.

While visiting Palestinian Authority President Mahmoud Abbas in Bethlehem early Tuesday, Trump avoided mentioning the long-standing, internationally accepted proposal to resolve the Israeli-Palestinian conflict: creation of an independent Palestinian state beside a Jewish Israeli nation.

Palestinian leaders were disappointed.

“There’s not much detail there, as usual,” said Hanan Ashrawi, a senior official of the Palestine Liberation Organization. “He’s still on a learning curve and peacemaking is not a business deal.”

On Sunday, Trump used a speech to a summit of Arab and Muslim leaders in Riyadh to make his case against Iran, urging “nations of conscience” to isolate the Islamic Republic. For decades, he said, Iran has “fueled the fires of sectarian conflict and terror.”

But cutting off Iran, the second most populous nation in the Middle East after Egypt, won’t be easy.

The White House has signaled that it will not tear up the 2015 nuclear deal that Iran signed with six world powers, as Trump vowed during the campaign, unless the nation is caught cheating by resuming nuclear development.

International monitors say it is in compliance. Quitting now would alienate U.S. allies and could lead to precisely what the accord has successfully blocked: an Iranian race to build a bomb.

Iran’s newly re-elected president, Hassan Rouhani,invited the Trump administration into dialogue even as he mocked the president’s anti-Iran speech in Saudi Arabia, a country that he noted did not allow elections.

Some diplomats worry the new White House is taking sides in the bitter Sunni-Shiite divide without fully understanding the history or implications.

Trump has made fighting terrorism a keystone of his domestic and foreign policy so far, focused on eliminating the threat from Islamic State, al-Qaida and other extremist networks that directly attack the West. Both groups are Sunni Muslims.

The U.S. and its allies continue to see Tehran as a malign force, chiefly because it supports a series of militant groups in the region: Hamas in Gaza, Hezbollah in Lebanon and the Houthis in Yemen, as well as President Bashar Assad’s government in Syria.

Trump has restored or expanded military aid and intelligence sharing to Riyadh that the Obama administration trimmed because of reports of indiscriminate bombing by Saudi warplanes in Yemen, where it leads a military coalition against the Houthis.

Trump also agreed during his visit to sell U.S. warships, fighter planes, an anti-missile system and other weaponry to the Saudis, which view Iran as their primary enemy.

“The Saudis have (Trump) right where they want him,” said Bruce Riedel, a former CIA analyst who now is a Middle East fellow at the nonpartisan Brookings Institution in Washington. “He has divided the Muslim world into good and evil, white and black. The Saudis are the good and white, Iran is the black and evil. It’s exactly the script the Saudis wanted, and it’s the script Trump gave them.”

tracy.wilkinson@latimes.com