The Only Party That Clearly Violated International Law in the Strait of Hormuz Is Not Iran

For weeks, a large part of the world — from the Arab Gulf states to Europe — has accused Iran of violating international law by regulating traffic and levying fees on ships transiting the Strait of Hormuz. In the UN Security Council alone, multiple resolutions have been introduced to condemn Iran's regulatory measures in the Strait, one of which passed with the support of roughly 140 member states. Hours before the United States and Iran agreed to a two-week ceasefire on April 7, eleven members of the Security Council voted in favor of another resolution (ultimately vetoed) that would have condemned Iran and authorized every UN member state to wage war against her to open the Strait.

By contrast, not a single resolution has been tabled before the Council condemning the US–Israeli war against Iran. The disparity between these two responses bears no relation to the fact that only one party has unambiguously violated international law — and that party is not Iran.

The US–Israeli war is unquestionably illegal; it constitutes one of the gravest crimes under international law: the crime of aggression. The legality of Iran's regulation of the Strait, on the other hand, is a far less clear-cut matter. Although Iran has not imposed a formal blockade, she has required ships to coordinate with her and to comply with her traffic-regulation regime during the period of war and ceasefire, and has outright barred vessels linked to the United States and Israel from transit. As of today, Iran appears to be permitting all commercial ships to pass (with the exception of those linked to America and Israel) throughout the ten-day Israel–Lebanon ceasefire, provided they use a "coordinated corridor" that runs close to the Iranian coast. There have also been reports of Iran charging fees on some transiting vessels. Unlike the United States, Iran can plausibly argue that she is exercising her rights under international law.

Rather than reflecting these facts, the international community has effectively treated Iran — not the two states that launched an illegal war against her — as the pariah. This tracks with long-standing Western tendencies to weaponize international law to legitimize imperial conduct, while constraining "Global South" states that resist Western hegemony. The resisting states are portrayed as serial rule-breakers; the states of the imperial core are presented as trustworthy and rule-abiding. The truth is exactly the reverse.

What does the law say?

States are legally forbidden from waging war except in self-defense — a narrow right — or under Security Council authorization. That means war and the threat of war cannot be used to coerce another state into concessions on its nuclear or missile program. That is precisely what the US and Israel sought when they launched their war on February 28.

Despite the glaring illegality, the Trump administration has attempted to offer threadbare justifications for the joint attack, framing it as "defensive." No one has been persuaded. In fact, most Western governments have not even condemned US–Israeli actions; days after the war began, German Chancellor Friedrich Merz went so far as to suggest that Iran does not even deserve the protection of international law.

The recent American move to impose a naval blockade on Iranian ports is likewise plainly unlawful. A blockade is a textbook act of aggression unless justified by self-defense or a UN resolution. It also violates the laws of naval warfare, which prohibit blockades whose incidental harm to civilians is disproportionate to the direct military advantage. The objective here is not military but political — to maximize Washington's leverage at the negotiating table — and it is designed to devastate the Iranian economy, inflicting catastrophic harm on civilians.

The status of the Strait of Hormuz

Iran's regulation of the Strait, by contrast, is not "black and white." Contrary to what some claim, the Strait is not "international waters"; it is an "international strait" composed exclusively of the territorial waters of two states: Oman and Iran.

Iran's critics lean on the UN Convention on the Law of the Sea (UNCLOS), which imposes the "transit passage" regime forbidding coastal states from impeding shipping. But Iran is not a party to UNCLOS, and neither is the United States. Under international law, states are bound only by treaties they have signed and ratified. Iran, though she signed in 1982, has pointedly refused to ratify — precisely because she rejects the "transit passage" rule.

Even if one argued the rule had hardened into "customary international law," Iran qualifies as a "persistent objector," which exempts her from the obligation. Iran can therefore plausibly claim to be governed by an older and more permissive regime — innocent passage. Under innocent passage, a coastal state may take measures to protect its security and may charge fees for "specific services" (such as navigational pilotage), both of which Iran can credibly claim to be providing given the risks of the ongoing armed conflict.

Imperial law as a weapon

Presenting a one-sided account of Iran's legal obligations, and accusing her of holding "the global economy hostage," is an attempt to cast her as the perpetrator of the gravest of crimes — while the actual crime of aggression committed by the US and Israel is waved away. This is how international law is weaponized to marginalize Global South states and strip them of sovereignty.

The very concept of "freedom of the seas" was itself a product of eighteenth-century imperial interests, designed to guarantee Western powers access to far-flung resources. Today, the objective of pressuring Iran over the Strait is not merely to secure navigation — it is to ensure her continued economic strangulation through sanctions, preventing her from generating any income from the Strait, so that she remains weak and unable to threaten great-power interests.

Lawyers may disagree about Iran's right to regulate the Strait. What is not up for debate is the illegality of the US–Israeli war and the current blockade. The international community's acquiescence to this double standard is a ratification of the legacy of "imperial international law" — a legacy the world must resist.

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*Maryam Jamshidi is Associate Professor of Law at the University of Colorado Law School.*