US Secretary of State Marco Rubio began a three-day tour of Gulf capitals in Abu Dhabi on Wednesday, the first high-level diplomatic mission since Washington and Tehran signed a memorandum of understanding that halted four months of hostilities. Speaking on arrival, Rubio said the visit was designed to hear the economic and security concerns of regional partners and to discuss issues left outside the formal accord, including the role of Iranian-backed proxies and freedom of navigation through the Strait of Hormuz. “That most certainly will come up in these discussions,” he told reporters when asked whether allies’ disquiet over the deal would be addressed.

Viewed from Gulf capitals, the terms struck by President Donald Trump’s administration are regarded as unexpectedly generous to a regional adversary. Officials in the United Arab Emirates, Kuwait and Bahrain have expressed particular alarm over a proposed $300 billion reconstruction fund, which they assess could be diverted by Tehran to rebuild military capabilities degraded during the conflict. The memorandum also contains no provisions limiting Iran’s ballistic missile programme, a long-standing demand of Gulf states that were struck by thousands of Iranian missiles and drones during the war. The UAE alone absorbed more than 2,800 projectiles, suffering civilian casualties and an exodus of expatriate workers that has strained its non-oil economy. According to regional security assessments, Iran has also established covert operational cells in Iraq that conducted at least seven drone attacks against Saudi, Kuwaiti and Emirati targets in April and May.

From Washington, the administration has presented the deal as a decisive strategic victory. Trump asserted that Iran’s military, leadership and radar systems have been “totally wiped out” and that International Atomic Energy Agency inspections would occur “100% at the appropriate time.” Iranian officials, via state media, immediately contradicted that claim, stating that Tehran had made “no new commitments” regarding nuclear inspections. Rubio, a former Senate hawk on Iran, framed the diplomatic opening as a test of whether Tehran’s leadership chooses to be “a country instead of a revolutionary movement that exports terror,” while insisting that Lebanon ceasefire talks are a separate track negotiated directly with Beirut. The balancing act is politically delicate: many congressional Republicans view the accord as capitulation, and Rubio’s own limited role in the Switzerland talks—led by Vice President JD Vance—has drawn scrutiny inside a party where both men are seen as potential successors to Trump.

Rubio’s itinerary includes meetings with Emirati leaders, a stop in Kuwait, and a Gulf Cooperation Council session in Bahrain. He invoked existing international law to reject any suggestion that states bordering the Strait of Hormuz could impose tolls on shipping, a reference to recent Iranian and Omani statements. The Lebanon dossier is advancing in parallel, with US-mediated talks between Beirut and Israel underway in Washington. Rubio characterised the overall process as “a work in progress,” noting that groundwork was laid over the preceding 72 hours but that “a lot of work remains to be done.” The GCC meeting on Thursday is expected to produce a collective Gulf position on the memorandum, while technical US-Iran discussions are set to continue within the 60-day negotiating framework.