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The United States and Iran have both imposed blockades on the Strait of Hormuz, but legal experts say the two actions are not equivalent under international law. While the US blockade may be lawful if it meets specific criteria, Iran's approach—which includes passage fees and alleged targeting of neutral vessels—has been described as being 'very close' to piracy.

Coverage Comparison

Two news outlets, Dawn and The Jerusalem Post, have examined the legal frameworks governing the strait. The Jerusalem Post, in an interview with maritime law expert Adv. Yoav Harris of Harris & Co. Maritime Law Office, focused on the legality of the US blockade under the San Remo Manual, a set of rules governing naval warfare. Dawn, authored by law professors, provided a technical analysis of Iran's proposed 'smart management' system under the United Nations Convention on the Law of the Sea (UNCLOS) and customary international law.

Key Claims

US Blockade Legality

According to The Jerusalem Post, a US blockade of the Strait of Hormuz can be legal if it adheres to the San Remo Manual. Harris explained that the manual requires that belligerents and neutral states be made fully aware of the blockade, that it be effective, enforced impartially against vessels from all nations, and that it not be established for the sole purpose of starving civilians. Additionally, humanitarian relief must be allowed to reach the civilian population if it is inadequately provided for.

The US blockade followed Iran's announcement of its own blockade on March 4, 2026, shortly after the US and Israel began striking Iran, as reported by The Jerusalem Post.

Iran's Actions

Iran's blockade has been criticized for failing to distinguish between enemy and neutral vessels. The Jerusalem Post reported that Iran targeted ships that allegedly failed to coordinate with the regime, and an Iranian official, Ebrahim Jabbari, announced that only friendly countries would be allowed to cross. A legal expert quoted by The Jerusalem Post stated that Iran's actions are 'very close to what is defined as piracy under the UN Convention,' which refers to acts of violence carried out by a vessel or aircraft against other vessels.

The Jerusalem Post also reported that Iran intends to generate $40 billion annually through transit fees and insurance requirements. It further noted that former US President Donald Trump had proposed a 20% fee on cargo transiting the strait but dropped it in favor of trade deal reimbursements. A legal expert cited by the outlet emphasized that providing protection against piracy is a legal obligation that cannot be conditioned on payment.

Legal Framework for Iran's Fee System

Dawn's analysis examined Iran's plan to establish a 'smart management' system for the strait, including passage fees. The outlet noted that UNCLOS recognizes two principal regimes for passage through international straits: innocent passage and transit passage. Innocent passage, which applies within a coastal state's territorial sea, is more restrictive and must be continuous and expeditious. Under Article 25(3), a coastal state may temporarily suspend innocent passage in specified areas without discrimination if necessary for its security and after due publication.

Iran has argued that the Strait of Hormuz falls under a special category of straits to which the innocent-passage regime applies, similar to the Straits of Tiran, as mentioned by Dawn. However, the innocent-passage regime prohibits imposing a fee merely for the right of passage, according to the 1958 Convention and UNCLOS principles.

Iran's domestic law treats the strait as subject only to the innocent-passage regime, Dawn reported. The country signed UNCLOS in 1982 but never ratified it, and the US is also not a party to the convention. The Vienna Convention on the Law of Treaties, Article 34, states that treaties do not create obligations for non-parties, Dawn noted. Without a multilateral treaty, Iran lacks a clear legal basis for compulsory tolls, the outlet argued.

Iran has cited precedents such as Turkey's Montreux Convention and Egypt's Suez Canal arrangements, but Dawn's analysis suggests these may not provide a solid foundation for unilateral fees. Iran extended its territorial sea to 12 nautical miles in 1959, citing security concerns, which is relevant to the applicability of the innocent-passage regime.

Perspectives

US and Israeli Perspective (via The Jerusalem Post)

The US blockade is presented as lawful under the San Remo Manual if it meets specific conditions, while Iran's actions are characterized as illegal and close to piracy due to indiscriminate targeting and the imposition of fees without legal basis.

Iranian Perspective (implied in Dawn's analysis)

Iran's approach is framed as an attempt to 'recalibrate' control over the strait, relying on legal arguments about the strait's classification and citing precedents from other waterways. The analysis suggests Iran may argue that the innocent-passage regime allows for temporary security measures, though the fee system remains legally questionable.