20APR

Iran: only allied ships may pass Hormuz

2 min read

10:10UTC

← Back to Two unsigned rulebooks collide at Hormuz Jump to analysis ↓

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

Read original →

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

Read story →

Trump claims Hormuz prize; Iran silent

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

Occurred 24 Mar 2026

Read story →

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

Read story →

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

Read story →

Different Perspectives

Israel

IDF Chief Eyal Zamir declared on 3 June there was no ceasefire for his forces, and strikes killed at least 10 civilians and one Israeli soldier on 4 June. The IDF killed Hezbollah's chief engineer and warned three south Lebanon villages to evacuate on 5 June, advancing into ground the unsigned Washington framework has not caught.

Hezbollah / Lebanon

Naim Qassem rejected the Washington Lebanon framework on 4 June as "absurd, humiliating and insulting", blocking a ceasefire instrument that required Hezbollah to withdraw north of the Litani before any Israeli withdrawal. Over one million Lebanese remain displaced; the framework's collapse prolongs that toll.

Iran

Foreign Minister Araghchi publicly coupled the Lebanon ceasefire to the Iran-US nuclear track on 4 June, carrying IRGC authority rather than his own civilian mandate. The IRGC delegation has sent no HEU counter-proposal since Araghchi confirmed no progress that same day; Mojtaba Khamenei's 21 May order to keep the 440.9 kg stockpile inside Iran remains operative.

United States

Rubio placed the Iran-US deal at 95 per cent complete on 4 June while the administration signed no Iran instrument and OFAC designated only Cuban targets. Trump separately disclosed and rejected an airlift plan to collect Iran's HEU stockpile, claiming the material is "entombed", a claim the IAEA cannot verify.

China

Beijing's MOFCOM Blocking Rules constrain OFAC enforcement on the mainland; China has not corroborated Trump's verbal account of any bilateral summit, and the rial's failure to hold its Rubio bounce, combined with the IRGC's stablecoin rail closure, increases Chinese yuan-denominated oil-payment exposure through Hormuz.

Bahrain

The IRGC struck Bahrain on 3 June as its sirens sounded and its PAC-3 magazine neared exhaustion; excluded from Rubio's 2 May emergency resupply, Bahrain received a 50-round Federal Register notice on 1 June on an 18-month delivery timeline, meaning it is defending the US Fifth Fleet headquarters on the last rounds it has.