Today, President Trump is to meet with Qatari Sheikh Tamim Bin Hamad al-Thani in the second step of a planned three-part diplomatic push to resolve a bitter dispute in the Persian Gulf region. The crisis erupted in June 2017 when Bahrain, Saudi Arabia and the United Arab Emirates (plus Egypt) severed diplomatic and economic ties with Qatar.

The U.S.-led reconciliation process had laid out a carefully sequenced set of meetings. Trump was to meet separately with Saudi Crown Prince Mohammed bin Salman and Emirati Crown Prince Mohammed bin Zayed, in addition to the Qatari emir. U.S. officials hoped these three bilateral meetings would lay the groundwork for gulf leaders to meet in Kuwait at the end of April to settle their differences before a planned summit at Camp David in May.

That plan now lies in tatters.

Mohammed bin Salman’s highly publicized visit to the United States produced little sign of movement. Mohammed bin Zayed of Abu Dhabi declined to visit the White House as originally planned on March 27. The Camp David summit has been postponed until September. What happened? And what happens next?

A bitter standoff

The crisis began in May 2017 with a hack of the Qatar News Agency, allegedly orchestrated by the UAE two days after Trump traveled to Riyadh and called upon the Arab world to unite against Iran. The four Arab states (the “Quartet”) severed ties with Qatar two weeks later and issued a set of 13 demands that focused on these key areas: Qatar’s relations with Turkey and Iran, support of regional media platforms and alleged ties to regional opposition groups.

The effect of U.S. personnel changes

Upheaval within the Trump administration probably affected the prospects for gulf reconciliation. Trump had sided initially with Saudi Arabia, and the UAE and accused Qatar of being soft on terrorism. Together with Defense Secretary Jim Mattis, then-Secretary of State Rex Tillerson had pushed the White House to find a mediated solution to the dispute.

Trump then reversed almost completely, from all but accusing Qatar of funding terrorism in June 2017 to publicly thanking Tamim for Qatar’s support in countering terrorism in January 2018. Many saw this as a triumph for Tillerson’s painstaking diplomatic approach and a rebuff to the Saudis and Emiratis.

Tillerson’s firing on March 13 was welcomed by some in Riyadh and Abu Dhabi who hoped it would lessen, if not derail, the administration’s diplomatic push for a Camp David reconciliation. The nomination of CIA Director Mike Pompeo as the next secretary of state encouraged Saudi and Emirati leaders, as he is known to be a policy hawk whose views on the Muslim Brotherhood and Iran align closely with their own.

Emirati and Saudi pushback

Tillerson’s sequential array of meetings fell apart when the Emiratis announced that Mohammed bin Zayed did not wish to visit between the other leaders and would go last. The animosity that triggered the Qatar dispute probably traced its roots more to Abu Dhabi than Riyadh, so delaying his visit until May would have enabled Mohammed bin Zayed to have the final word on whatever deal put on the table for Camp David.

Shifting the Camp David time frame to September buys the White House time. During Mohammed bin Salman’s visit to Washington, the Saudis made it clear they would not accept external mediation and would resolve the crisis within a regional framework instead.

Intractable dispute

The Saudi visit and Emirati delay has concentrated minds in Washington on just how intractable the gulf dispute has become. While the Quartet insists that Qatar comply with their 13 demands before negotiations can begin, the Qataris call for dialogue without preconditions and rejected the Quartet’s conditions as an unacceptable intrusion of sovereignty. Qatar’s Tamim told Charlie Rose last fall that if the Quartet was prepared “to walk one meter toward me, I’m willing to walk 10,000 miles toward them.” Such has been the impasse that this sentiment has not yet been tested.

A few remaining wild cards

Two wild cards may yet shift the landscape by September and ensure Camp David never occurs at all.

The first is the uncertainty regarding the administration’s policy toward the Iran nuclear deal, given the appointment of John Bolton as national security adviser and Trump’s May 12 deadline for making a final decision about the agreement. Iran ­— and forthcoming talks on North Korea — will probably monopolize decision-making at the State Department and the National Security Council in the next few months, further contributing to the loss of momentum caused by Tillerson’s exit.

The second is the apparent direction of special counsel Robert S. Mueller III’s inquiry into foreign interference in the 2016 presidential election. The Mueller investigation appears to have broadened in scope to encompass alleged attempts from the UAE to influence members of the incoming administration as it took office and in the run-up to Trump’s meeting with gulf leaders in Riyadh in May 2017. The Emirati leadership is facing the prospect that they could be dragged into the controversy that hitherto has been concentrated primarily on Russia.

What could be next?

Qatar has responded to the crisis by strengthening its relationship with the United States. Qatar became the first Persian Gulf country to sign a Memorandum of Understanding with the United States on counterterrorism and convened a Qatar-U.S. strategic dialogue. These measures built upon Trump’s call at the Riyadh summit for closer defense and U.S. and gulf security ties.

The standoff in the region has polarized opinions in the region and in Washington. The failure of the Trump administration’s sequential mediation has illustrated the lack of interest in bringing it to an end through a negotiated settlement. With Camp David unlikely to happen, the chances that the dispute becomes permanent just got a lot higher.

Kristian Coates Ulrichsen is a research fellow for the Middle East at Rice University’s Baker Institute for Public Policy. He is on Twitter @Dr_Ulrichsen.