Iran released 28 dual nationals at a Doha handover on Saturday in exchange for nine detainees held in U.S., Israeli and European custody, the largest swap since the April ceasefire and an outcome that Qatari and Omani mediators said was designed to bank political momentum four days before the multinational reconstruction conference convenes in Marseille.

The exchange, brokered over thirteen days of shuttle diplomacy between Doha, Muscat and Tel Aviv, was finalized in two stages at Hamad International Airport beginning shortly after 4 a.m. local time. A chartered Qatari Emiri Air Force Boeing 747 carried twenty-two of the released dual nationals to a transit lounge cordoned off from commercial traffic, where consular officials from seven countries had been waiting since Friday night. A second aircraft, a Swiss government Falcon 7X, arrived four hours later from Tehran with the remaining six detainees, including two Australian academics and a French-Iranian researcher whose families had campaigned publicly for nearly three years.

“This is the largest single humanitarian return since the war ended, and the first in which a European-Iranian dual national held on national security charges has been released without a conviction being formally rescinded,” Qatari Prime Minister and Foreign Minister Mohammed bin Abdulrahman Al Thani told reporters in the airport’s diplomatic terminal shortly after the second aircraft landed. “The parties have shown that the framework can deliver in human terms. That matters for what comes next.”

Among those released on the Iranian side were sixteen European, four Australian, three Canadian and five U.S.-Iranian dual nationals, according to a manifest reviewed by reporters at the airport. Two of the U.S.-Iranian detainees were released on what Iranian state media described as “humanitarian medical grounds” without a formal sentencing review.

In exchange, the United States, Israel and three European governments released nine individuals, including four Iranian nationals serving sentences in U.S. federal prisons on sanctions-evasion and procurement-related charges and three described in an Israeli government statement as “operatives with documented ties to Iran-aligned networks in the Levant.” The releases were approved by Israel’s reconstituted security cabinet on Thursday evening following nearly twelve hours of debate.

Israeli participation had been the chief obstacle to the exchange, according to three regional diplomats granted anonymity to discuss confidential talks. The departure of two far-right ministers from Prime Minister Benjamin Netanyahu’s coalition last week, and the subsequent entry of the National Unity bloc led by Benny Gantz under an interim accord finalized Wednesday, opened a narrow window for cabinet approval that mediators had been waiting nearly two weeks to exploit. “Without the Gantz arrangement, this exchange does not happen this weekend,” one of the diplomats said. “It might not have happened at all before Marseille.”

President Donald Trump, in remarks delivered shortly after dawn at Joint Base Andrews before departing for an event in North Carolina, said the released Americans were “coming home where they belong” and credited what he called “tough but smart diplomacy” by his administration. The president did not take questions and made no mention of the Iranian nationals released from U.S. custody, several of whom had been the subject of sealed indictments tied to alleged procurement of dual-use technology between 2019 and 2023.

Secretary of State Marco Rubio, who flew to Doha overnight to meet the released Americans on the tarmac, struck a more measured tone. “This is a humanitarian outcome that the framework made possible,” Rubio said in a brief statement before boarding the aircraft for the return flight to Joint Base Andrews. “It is not a vindication of the regime that detained them. It is a recognition that diplomacy, conducted with leverage, produces results that war does not.”

Iranian Foreign Minister Abbas Araghchi, addressing reporters at Mehrabad International Airport in Tehran after seeing the Iranian returnees onto a domestic flight to Mashhad, said the exchange demonstrated that “Iran honors its undertakings when others honor theirs.” Araghchi praised Qatar and Oman, thanked Switzerland for its protecting-power role, and made a pointed reference to “the small group in Tel Aviv that tried to make this difficult and failed.” He said the Supreme National Security Council had endorsed the swap unanimously on Wednesday and that President Masoud Pezeshkian had personally telephoned each of the returning Iranian nationals’ families.

The exchange unfolded against the backdrop of a ceasefire that has held for seventeen days without serious incident and a sanctions-sequencing roadmap finalized in Geneva on Monday that Iranian institutions are reviewing this weekend. Diplomats said the timing was deliberate. The Marseille reconstruction conference, scheduled to open Wednesday at the Palais du Pharo, is expected to draw foreign ministers from more than forty countries, an initial multilateral pledge round projected by French organizers at between $38 billion and $45 billion, and the first public appearance of Iranian Deputy Foreign Minister Majid Takht-Ravanchi at a Western-hosted event since the war began.

“The prisoners are the test the parties needed to pass before Marseille,” said Layla Hassan, a Beirut-based regional analyst with the Carnegie Middle East Center. “If the swap had collapsed, the political case for a $45 billion reconstruction round would have collapsed with it. The mediators understood that. So did the families.”

Markets, which have grown progressively less sensitive to Middle East political news since the ceasefire took effect, took the announcement in stride when it broke overnight. Brent crude futures opened the new week’s electronic trading in Asia largely unchanged near $93 a barrel, while the shekel firmed 0.3 percent against the dollar and the Iranian rial recovered roughly 4 percent on the Tehran open-market quote, its strongest single-session gain since February. “The market is treating the exchange as a confirmation rather than a surprise,” said John Reilly, an analyst at Citi who tracks Gulf risk. “Confirmation is still valuable. It tells you the framework can convert architecture into outcomes.”

In Washington, the State Department said the five returning U.S.-Iranian dual nationals would be flown overnight to Joint Base Andrews and reunited with families at a private reception hosted by Vice President JD Vance on Sunday afternoon. A senior administration official, briefing reporters at Foggy Bottom, said the administration was already in preliminary discussions with mediators about a possible third exchange tranche covering remains and what the official called “long-term security detainees on both sides whose status touches the most sensitive part of the file.”

Mediators in Doha said working groups would reconvene Monday morning to begin formal preparations for Marseille, including a coordination session on the structure of the conference’s pledge mechanism. Officials said additional announcements on the composition of national delegations and the agenda of the opening session would follow before the weekend was out.