What Does Iran’s Strait of Hormuz Management Plan Change?

Oral Toğa

Apr 7

7 min read

For decades Iran has kept the threat of closing the Strait of Hormuz on the agenda. Similar rhetoric was repeated during the Tanker War of the 1980s, in the sanctions crisis of 2012 and in the tanker seizures of 2019, and on each occasion it remained at the level of a threat.

The “Strait of Hormuz Management Plan,” adopted in March 2026 by Iran’s legislature, the Islamic Consultative Assembly, differs qualitatively from those earlier instances. The measure asserts sovereignty, control and surveillance over the strait, provides for the levying of transit fees and imposes restrictions on vessels belonging to certain countries.

With this step the approach to control of the strait has for the first time been carried into the domain of domestic law, and Tehran’s search for a more permanent status for the post-war period has become plainly visible.

On what legal ground does the Hormuz regime rest?

The principal reference point for the right of passage through international straits is the Corfu Channel Case. In that judgment the International Court of Justice held that in peacetime the warships of states may pass through straits used for international navigation without obtaining the prior authorization of the coastal state. It was considered sufficient that the passage be “innocent” in character. The coastal state has no power to prevent or suspend such passage. The 1958 Geneva Convention on the Territorial Sea likewise provided expressly, in Article 16(4), that innocent passage through international straits may not be suspended.

The extension of territorial seas created a critical threshold in this field. When Iran in 1959 and Oman in 1972 extended their territorial seas to 12 nautical miles, the high-seas corridor through the Strait of Hormuz disappeared and the strait fell entirely within overlapping territorial waters. The UNCLOS III negotiations produced an answer to this problem in the formula of “transit passage.”

This regime, set out in Articles 37 to 44 of the United Nations Convention on the Law of the Sea, is structurally distinct from innocent passage. Article 44 expressly provides that transit passage may not be suspended under any circumstances. Within this framework aircraft may overfly the strait and submarines may transit submerged. It is not open to the coastal state to impose a requirement of prior authorization or to demand a fee. Its regulatory competence is defined by limited fields such as maritime safety, environmental protection, fishing and customs.

In this framework the Strait of Hormuz is a strait connecting exclusive economic zones and used for international navigation. Carrying roughly a quarter of the oil traded by sea worldwide and a fifth of global LNG trade, this narrow waterway stands out as one of the most critical fields of application of the transit passage regime.

Why does Iran not recognize transit passage?

Iran’s objection to the transit passage regime is neither new nor superficial. When it signed the United Nations Convention on the Law of the Sea on 10 December 1982, Tehran issued a simultaneous declaration stating expressly that transit passage does not reflect customary law and that only states party to the convention may benefit from that right. The convention has never been ratified.

Domestic law is consistent with this stance. The 1993 Act on the Marine Areas of the Islamic Republic of Iran makes no reference to the concept of transit passage. Article 5 recognizes the passage of foreign vessels only within the scope of innocent passage. Article 9 imposes a requirement of prior authorization for warships, nuclear-powered vessels and ships carrying hazardous materials. Article 8 grants the government the power to suspend innocent passage. These provisions stand in open contradiction with the transit passage regime of UNCLOS.

One of the strongest foundations of Iran’s legal defence is the persistent objector doctrine. The concept of transit passage was objected to before it took shape within the UNCLOS framework, the objection was placed on record by formal declaration at the signature stage, it was reflected in domestic law in 1993, and it has been sustained as a consistent state policy for more than forty years.

The counter-argument advanced against this is also strong. For many years Iran in practice permitted transit passage. Regular transits of the Strait of Hormuz by the US Navy continued and commercial maritime traffic was not obstructed. The Freedom of Navigation Program the United States has conducted since 1979 has also carried out and recorded these transits systematically. It is argued that this de facto situation weakens Iran’s claim of persistent objection.

Even so, the debate has reached no settled conclusion at the academic level. By the criterion set out by the International Court of Justice in the 1969 North Sea Continental Shelf Cases, in the formation of customary law the practice of “states whose interests are specially affected” is regarded as decisive. In the Hormuz context those states are Iran and Oman, and neither has given place to the transit passage regime in its domestic law. On the other hand, in one of the world’s most critical maritime straits, the fact that Iran and the United States, two of the principal parties, are not party to UNCLOS produces a striking paradox.

What does the new law introduce?

The content of the Strait of Hormuz Management Plan can be grouped under four headings. First, the measure sets out plainly Iran’s claim to sovereignty, control and surveillance over the strait. Second, a transit fee denominated in Iranian rials is envisaged. According to information that has reached the press, for large-tonnage vessels the sum is in the order of two million dollars. Third, while vessels of the United States, Israel and countries applying sanctions to Iran are barred from passage, ships flagged in China, Russia, India and Pakistan are granted selective transit. Fourth, the measure provides for the preparation of a joint maritime protocol with Oman.

Implementation in practice began before the law was adopted. A control point operated by intermediaries connected to the Islamic Revolutionary Guard Corps was established between Qeshm Island and Larak Island, route codes were issued to vessels and payments began to be collected. It has also been reported that some payments were made in Chinese yuan.

The essential element distinguishing this measure from earlier threats is its strategic positioning for the post-war period. Iran has raised recognition of its sovereignty over Hormuz as one of the five conditions it has put forward for ending the war. This shows that control of the strait has moved beyond being a tactical instrument and has become a permanent demand of the state.

The international reaction has been severe. In Resolution 2817 of 11 March 2026 (with China and Russia abstaining), the United Nations Security Council condemned Iran’s attacks on Gulf states and defined obstruction of transit passage through the Strait of Hormuz as a threat to international peace and security. The G7, for its part, stressed the imperative of safe and fee-free navigation.

The prevailing view in legal circles is that the levying of transit fees has no basis in international law. At the same time, some assessments show that while the transit passage regime is strongly protected at the doctrinal level, serious difficulties can arise in practice where a coastal state is prepared to violate those rules.

Why is the Oman equation critical?

Oman controls the southern shore of the Strait of Hormuz through the Musandam Peninsula. The traffic separation scheme established by the International Maritime Organization passes through Omani territorial waters at the narrowest point of the strait. This makes Oman an indispensable actor in any debate over a possible new regime. It does not appear possible for Iran to regulate the strait in law on its own.

Oman’s own position displays a striking duality. Although it ratified the United Nations Convention on the Law of the Sea in 1989, its Royal Decree of 1981 recognizes only innocent passage and requires prior authorization for warships. That a party to UNCLOS maintains a domestic practice inconsistent with its own convention illustrates the scale of legal uncertainty at Hormuz. Relations between the two countries are deep. The continental shelf agreement of 1974 also includes reciprocal patrol rights.

The statement made in early April by Iranian Foreign Minister Abbas Araghchi, that “after the war, the Hormuz arrangements are a matter between Iran and Oman,” reflects this dynamic plainly. That approach offers no framework compatible with the multilateral structure of UNCLOS.

Oman, for its part, is maintaining a policy of “strategic silence.” While hosting US-Iran contacts in Muscat, it has set out no clear position on Iran’s claim of sovereignty.

What does the picture tell us?

Three main scenarios stand out as to where matters are heading. The first is the reopening of the strait by military means. In the first weeks of the conflict the US Navy neutralized a large number of Iranian naval assets. Even so, the mine threat in areas close to the coast, coastal defence missiles and the possibility of escalation in a narrow waterway make this option a costly one. The second scenario is a return to the pre-war status quo. That possibility requires Iran to withdraw the measure it has brought into force. Without a comprehensive peace agreement this scenario appears difficult to realize. The third and more likely scenario is that Iran maintains the control mechanism as leverage and the process evolves through negotiation into a new arrangement. The bilateral protocol raised on the Iran-Oman line is regarded as among the first signs of this tendency.

What is most striking is the precedent effect the measure may create. A coastal state levying fees unilaterally on a natural international strait and applying selective passage could pave the way for similar demands at other critical chokepoints, from the Bab el-Mandeb to the Strait of Malacca. This carries an effect capable of generating new areas of tension among the global powers.

Iran’s invocation of the Suez Canal is not a valid comparison in legal terms. Suez is an artificial waterway belonging to a particular state. It cannot be placed in the same category as a natural international strait. Even so, the precedent effect can arise independently of legal consistency. The Turkish Straits, on the other hand, have a sui generis status regulated by the Montreux Convention. Because Türkiye’s sovereignty and regulatory authority are recognized by an international treaty, they are not directly affected by Iran’s unilateral steps.

The Strait of Hormuz Management Plan constitutes the most comprehensive and concrete challenge directed at the transit passage regime since 1982. In earlier crises the absence of a binding text made a return to the old order easier once the tension had passed. Today a law in force distinguishes the situation from those earlier instances. What is more, this measure forms the legal basis of one of the demands Iran has placed among its conditions for peace. For that reason the end of the war does not mean the law will disappear. As long as the measure remains in force, the legal status of the strait will continue to be contested.

This article was first published in IRAM on April 7, 2026.