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Iran: only allied ships may pass Hormuz

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ConflictDeveloping

Iran's UN representative Ali Mousavi told the International Maritime Organisation this week that vessels belonging to or linked to 'aggressor parties' forfeit the right of innocent passage through the strait of Hormuz. ¹ PressTV, Iran's official state broadcaster, confirmed the statement as Iran's official legal position. Permitted countries under the vetting system are India, China, Russia, Iraq, and Pakistan.

The IMO statement is the formal legal scaffolding for the parliamentary toll bill being drafted simultaneously. Iran is constructing a two-layer legal architecture: domestic statute (the Majlis bill) combined with formal international notification (the IMO submission) that pre-empts claims that Iran is acting without legal notice. The IMO notification mirrors Egypt's communication to the Suez Canal Users Association in 1956 after nationalisation.

Trump had claimed Iran offered Hormuz concessions , and Pakistan confirmed the 15-point US proposal . The IMO statement directly contradicts the framing that Iran is moving toward reopening the strait: Iran is doing the opposite, establishing formal legal grounds for continued selective passage that would survive any ceasefire under the pending domestic legislation. Pentagon planning for a Kharg Island assault continues ; the IMO statement is Iran's legal counter-move to that planning, establishing that any forcible passage would constitute a violation of Iran's defined legal framework rather than merely a military confrontation.

Deep Analysis

In plain English

Iran told the international shipping authority that ships linked to countries attacking it lose the right to pass through the Strait of Hormuz freely. This would let Iran legally charge or block ships from the US, Israel, and their allies. International law says countries cannot block international waterways, but Iran argues it is defending itself.

Deep Analysis

Root Causes

Iran is exploiting a gap in UNCLOS: the convention assumes coastal states will not be at war with the states whose vessels transit their waters. The legal framework was not designed for a scenario where a coastal state is under active military attack.

By framing the toll as a defensive measure rather than an offensive blockade, Iran creates legal ambiguity that is harder to challenge than a straightforward closure.

Source Landscape

This story draws on mixed-leaning sources from Israel

Israel

Primary parallel: Libya declared the Gulf of Sidra a closed bay in 1973, claiming sovereignty over international waters. The US challenged Libya's claim with naval exercises in 1981 and 1986, leading to military confrontations. Libya's legal position was never accepted by any international court.

Counter-parallel: Iran's position is stronger than Libya's: Iran actually controls three sides of the strait of Hormuz, and the toll system is generating revenue and operating in practice. Libya never achieved physical control over the Gulf of Sidra.

Consensus view: The International Maritime Organisation's Legal Committee and UNCLOS scholars assess that the right of innocent passage through international straits cannot be unilaterally revoked by a coastal state. Iran's claim has no precedent in modern maritime law.

Counter-view: Iran argues that UNCLOS Article 25 permits a coastal state to take necessary steps to prevent passage that is not innocent. Tehran frames the toll system as a defensive measure against states conducting military operations against it, which it argues terminates those states' right to innocent passage.

Key tension: Whether Iran's legal argument has enough ambiguity under UNCLOS to survive challenge, or whether it constitutes a unilateral rewrite of international maritime law.

Sources:Times of Israel / CENTCOM·Times of Israel / CENTCOM

Mentions:Kharg Island →

First Reported In

Update #49 · Hormuz toll into law; Tangsiri killed

Times of Israel / CENTCOM· 27 Mar 2026

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Causes and effects

Caused by

Pentagon plans to seize Kharg Island

Legal notification to IMO constructs formal basis for resisting forcible passage by US forces

Occurred 24 Mar 2026

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Trump claims Hormuz prize; Iran silent

IMO statement directly contradicts Trump's claim that Iran is offering Hormuz concessions

Occurred 24 Mar 2026

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This Event

Iran: only allied ships may pass Hormuz

Led to

Iran's five peace terms: Hormuz first

Iran's IMO notification revoking innocent passage for hostile parties is the international legal layer underpinning the five conditions, with Hormuz sovereignty as condition five.

Occurred 25 Mar 2026

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One ship through Hormuz in 24 hours

Iran's IMO legal notification on Hormuz sovereignty builds the international-law layer of the dual-architecture strategy reinforcing the de facto closure.

Occurred 29 Mar 2026

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Different Perspectives

UK Maritime Trade Operations

UKMTO logged six armed men boarding a tanker 136 nautical miles east of Al Mukalla on 20 August and redirecting it toward Somalia. A vessel steered toward the Somali coast reads as an attempted seizure, a distinct hazard from the stand-off strikes the same lane has seen before.

Mohammad Bagher Ghalibaf

Iran's Majlis speaker received Iraq's Hormuz carve-out request in Baghdad on 19 August, a request that treats passage as Tehran's to grant. Ghalibaf's authority over that grant sits alongside the Revolutionary Guard's separate transit rules, which have moved independently of Iran's foreign ministry before.

Haibat al-Halbousi

Iraq's parliament speaker asked Iran for special consideration on Iraqi Hormuz oil exports during Ghalibaf's 19 August Baghdad visit. Iraq presses the request from a weak position: Iran's central bank is simultaneously demanding Baghdad release Iranian reserves parked in Iraqi accounts.

Federal Department of Economic Affairs, Education and Research

Switzerland's economics ministry updated the Article 21 forms governing lawful Iran money transfers on 19 August, with only the revised forms accepted from 26 August. Bern operates one of the few remaining legal Iran payment channels and has just set a hard cutover on its control point.

Motegi Toshimitsu

Japan's foreign minister said in Muscat on 20 August that Tokyo wants closer coordination with Oman on safe Hormuz and Bab el-Mandeb passage. Japan has no naval presence of its own in the strait, so it is routing the ask through the state negotiating with Iran instead.

Badr bin Hamad Al Busaidi

Oman's foreign minister joined Japan's in Muscat on 20 August to call for intensified coordination on Hormuz and Bab el-Mandeb navigation. Oman also runs the mediation track with Tehran, so the appeal travels through the same channel as the negotiation.