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Iran Conflict 2026
31MAY

Five Gulf states reject Iran's sea route

3 min read
09:14UTC

Bahrain, Kuwait, Qatar, Saudi Arabia and the UAE wrote formally to the UN's maritime regulator around 21 May, telling commercial vessels not to use Iran's Hormuz transit route.

ConflictDeveloping
Key takeaway

Five Gulf states took Iran's Hormuz claim to the UN regulator; the mediator holding Iran's money signed it too.

Bahrain, Kuwait, Qatar, Saudi Arabia and the United Arab Emirates (UAE), five Gulf states and not all six, wrote formally to the International Maritime Organization (IMO) around 21 May, telling commercial vessels not to engage Iran's transit route or cross the strait through it 1. The IMO is the United Nations agency that sets the safety and security rules for international shipping, which makes it the one forum where Iran's claim to police the waterway meets a body that can answer with rules of its own.

The letter directly answers Iran's Persian Gulf Strait Authority (PGSA), the state body that published controlled-zone coordinates on 20 May reaching into Emirati and Omani waters, and that backs them with the rial-only toll system the Majlis passed the same week . By taking the dispute to the IMO, The Gulf states convert a bilateral stand-off into a regulatory contest, betting that the first credible multilateral text usually holds and later claims negotiate against it.

Qatar signed the rejection while holding the $12 billion in frozen Iranian assets that Tehran has named as its precondition for reopening Hormuz, and while mediating the US-Iran talks. Three roles, and they pull against each other. The mediator Iran depends on is publicly rejecting Tehran's Hormuz doctrine and sitting on the money Tehran most wants released.

The original freeze was a US Treasury instrument, which leaves Doha as the escrow holder rather than the decision-maker. It cannot release the funds without a Washington order, which means the mediator cannot bridge the one gap Tehran cares most about until the United States acts first. That is why the sequencing dispute will not resolve itself, and why a signature on an IMO letter and a seat at the negotiating table can sit, awkwardly, in the same set of hands.

Deep Analysis

In plain English

Five Gulf countries, Bahrain, Kuwait, Qatar, Saudi Arabia, and the UAE, sent a formal letter to the International Maritime Organization (IMO), the United Nations body that governs international shipping. The letter told shipping companies not to use the transit route Iran had set up through the Strait of Hormuz, or pay the tolls Iran was demanding. Iran had created a new body called the Persian Gulf Strait Authority (PGSA) to control who passes through the strait and charge fees in Iranian currency (rials) to do so. The Gulf states were saying: ignore that, it is illegal under international law, and we will not recognise it. Qatar signed the rejection letter while simultaneously sitting in the middle of peace negotiations between the US and Iran, holding $12 billion in Iranian money that Tehran wants returned as part of any deal. Doha signed the IMO letter to build legal protection for itself if the diplomacy collapses, while keeping the mediation channel open if it succeeds.

Deep Analysis
Root Causes

Iran's PGSA authority exploits a specific gap in UNCLOS architecture. The convention guarantees "transit passage" through international straits in Article 38, but Iran never ratified UNCLOS.

Tehran's domestic maritime law, updated in 2024, claims jurisdiction over any vessel linked to a state that has sanctioned Iran, a category broad enough to cover virtually all Western-flagged commercial traffic. The IMO has no direct enforcement power over a non-UNCLOS state operating its own transit framework inside its claimed territorial water.

Qatar's contradictory position, signing the IMO rejection while brokering the talks that could make the PGSA obsolete, reflects the GCC's structural exposure. If the MOU negotiation fails, the IMO letter creates a legal record protecting Gulf states from liability for any future vessel incidents at the PGSA coordinates. If the MOU succeeds, the PGSA dissolves and the letter becomes moot. Qatar has hedged both outcomes.

What could happen next?
  • Precedent

    The five-state IMO letter creates the international legal record needed for any future UNCLOS arbitration or flag-state compensation claim arising from PGSA enforcement actions against non-compliant vessels.

    Medium term · Assessed
  • Risk

    If Iran reads Qatar's IMO signature as evidence that Doha is not a neutral mediator, Tehran could use it to walk back from the Doha channel and demand a different venue.

    Immediate · Suggested
  • Consequence

    The letter provides commercial cover for shipping companies to refuse PGSA registration without facing their own flag-state liability, lowering the compliance rate for the PGSA's transit authority.

    Short term · Assessed
First Reported In

Update #108 · US strikes Bandar Abbas as deal talk stalls

Bloomberg· 26 May 2026
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Causes and effects
This Event
Five Gulf states reject Iran's sea route
The letter takes Iran's claim to control the strait to the one venue that issues binding shipping rules, and Qatar signed it while mediating the talks and holding the assets Iran wants released.
Different Perspectives
Iran human rights monitors (Amnesty International, Iran HRM, Hengaw)
Iran human rights monitors (Amnesty International, Iran HRM, Hengaw)
Monitors documented 30 women held on capital moharebeh charges in a basement prison ward, Benyamin Naqdi's death sentence with a forced-confession broadcast, and 39 political executions since February. Iran's security courts have processed protest cases at uninterrupted wartime tempo regardless of the diplomatic track.
Lloyd's of London (war-risk underwriters)
Lloyd's of London (war-risk underwriters)
Lloyd's held its Hormuz war-risk designation at $10-14 million per voyage while Brent fell 19%, maintaining a structural divergence from futures pricing. Underwriters require a UN Security Council resolution or government certification letter, not diplomatic optimism, before de-listing the strait.
Oman (Sultan Haitham's government)
Oman (Sultan Haitham's government)
Muscat issued a mine alert in its own territorial waters while denying any Hormuz toll plan after US Treasury threatened sanctions. A suspected mine in Omani waters on the same weekend as US financial pressure forces Muscat to demonstrate sovereignty without appearing to choose sides.
China (PRC)
China (PRC)
Beijing sent scholars rather than its defence minister to Shangri-La for the second year running and addressed Taiwan and multilateralism without mentioning Iran. China maintains its bilateral energy corridor protection with Tehran while refusing the diplomatic exposure of a public position at multilateral forums.
Iran Supreme National Security Council
Iran Supreme National Security Council
The SNSC framed the unsigned MOU as a 10-point Iranian victory with enrichment already recognised, and the foreign ministry rejected Trump's nuclear conditions within hours. Tehran treats each unsigned day as validation that Iran has retained its stockpile without surrendering it.
Trump administration (CENTCOM/White House)
Trump administration (CENTCOM/White House)
Trump posted three non-negotiable public conditions while CENTCOM disabled a commercial ship and Hegseth threatened resumed strikes from Singapore. The administration treats the unsigned MOU as leverage to extract maximum Iranian concessions before any ceasefire instrument is committed to paper.