On 13 April 2026, the United States took a step that shifted the tectonic plates of international maritime law. The announcement of a naval blockade of the Strait of Hormuz was framed as a strategic necessity: a move to cut off Iran’s oil revenues, force diplomatic concessions, and bring a swift end to regional conflict. However, from the perspective of a legal practitioner, the move is more than just a bold military maneuver. It is a fundamental breach of the rules-based order that has governed the high seas for decades.
At Del Canto Chambers, we monitor these developments not just for their geopolitical impact, but for what they signal to the international community regarding the stability of global commerce and the enforcement of international treaties. The legal position of this blockade is, quite simply, untenable.
Here is an analysis of what the law actually says, and why this precedent is so dangerous.
The Strait of Hormuz: A Test for International Maritime Law
The primary misconception in maritime disputes is that a coastal state can exert total control over a waterway based on proximity. Under the United Nations Convention on the Law of the Sea (UNCLOS), the Strait of Hormuz is defined as an “international strait.”
Under the United Nations Convention on the Law of the Sea (UNCLOS), specifically Articles 37 to 44, the Strait of Hormuz is defined as an “international strait.” It serves as the vital artery connecting the Persian Gulf to the Arabian Sea. The statistics are well-known to every energy trader and economist: approximately 20 per cent of the world’s global oil and one-third of global liquefied natural gas (LNG) pass through these waters every single day.
Because it connects the Persian Gulf to the Arabian Sea, it carries the strongest navigational protection provided by international maritime law: the right of transit passage.
Transit Passage: Why International Maritime Law is Non-Negotiable
To understand why the blockade is a violation, one must understand the core of maritime legal frameworks and the difference between “innocent passage” and “transit passage.”
In a nation’s territorial sea, foreign ships enjoy the right of “innocent passage.” However, a coastal state can, under certain conditions, temporarily suspend innocent passage if such suspension is essential for the protection of its security.
The drafters of UNCLOS recognized that applying the rules of “innocent passage” to vital chokepoints like Hormuz, Gibraltar, or Malacca would allow coastal states to weaponize global trade. Therefore, they established the regime of transit passage.
Article 44 of UNCLOS is categorical:
> “States bordering straits shall not hamper transit passage and shall publish appropriate publicity to any danger to navigation or overflight within or over the strait of which they have knowledge. There shall be no suspension of transit passage.”
The wording “there shall be no suspension” is not a suggestion. It is a hard legal floor. It was designed specifically to prevent any state: whether Iran or the United States: from closing the gate on global commerce. By announcing a blockade, the US has effectively attempted to suspend a right that the law declares unsuspended.
A Violation of International Maritime Law Against the World
The US Central Command’s announcement specified that the blockade would apply to vessels of all nations transiting to or from Iranian ports. This is where the legal argument for “targeted enforcement” collapses under the weight of international maritime law.
A blockade is not a scalpel; it is a blunt instrument that interferes with the sovereign rights of every state whose flagged ships use the strait. India, France, Singapore, South Korea, and dozens of other nations have ships currently transiting these waters. These states are not parties to the dispute between Washington and Tehran.
These nations hold transit passage rights independently of any bilateral conflict. To override these rights without an explicit mandate from the UN Security Council is a breach of UNCLOS, a violation of the UN Charter, and a departure from customary international law.
As international litigation experts know, a naval blockade is traditionally considered an act of war. In the absence of a Security Council resolution: which will not be forthcoming due to the certainty of Russian and Chinese vetoes: the United States is acting unilaterally. It is operating without legal cover in the world’s most sensitive maritime chokepoint
The Strategic Cost of Eroding International Maritime Law
Perhaps the most baffling element of this blockade is the long-term damage to the United States’ own legal standing. For over a decade, Washington has been the primary advocate for the “rules-based order” and international maritime law in the South China Sea. and the Taiwan Strait.
The US has repeatedly invoked UNCLOS transit passage rights to challenge Chinese claims, arguing that the universality of these rules is the only thing preventing global anarchy at sea. The US hailed the 2016 South China Sea arbitration award as a definitive vindication of these doctrines. Every “Freedom of Navigation Operation” (FONOP) conducted by the US Navy is premised on the idea that these rules apply to everyone, everywhere, at all times.
By breaking the rule in Hormuz, the US has handed its strategic rivals a gift. China has already condemned the blockade as a violation of the freedom of navigation. From a legal standpoint, Beijing is correct. The United States has provided a ready-made legal justification for China to restrict transit through the Taiwan Strait, using the very precedent Washington just established.
For those involved in arbitration and international dispute resolution, the erosion of these norms is deeply concerning. When the world’s most powerful maritime nation decides that rules are optional, the rules don’t disappear: but their authority certainly does.
What Actually Breaks: The Credibility of International Law
International maritime law has no standing navy to enforce its decrees. Its power is derived from three things: credibility, consistency, and the shared perception that rules apply to everyone.
In 1609, Hugo Grotius wrote Mare Liberum (The Free Sea), arguing that the sea cannot be enclosed or owned because human commerce requires it to remain open for the benefit of all. Four centuries later, that principle remains the bedrock of the global economy.
What has changed is that the very state most responsible for the modern enforcement of this principle is now the one dismantling it. The blockade may or may not achieve its short-term military objectives against Iran. However, it has already inflicted a serious, self-inflicted wound on the international legal order.
At Del Canto Chambers, we believe that the rule of law is the only stable foundation for international business and global mobility. When that foundation is shaken by unilateral action, the tremors are felt by every business, shipping line, and state that relies on the predictable application of the
The war may eventually end, but the legal precedent set by this blockade will outlast the current conflict. It is a reminder that the rule of law is fragile, and once broken, it is not easily mended.
For further insights into international law and how these global shifts affect your interests, you can explore our DCC News section or contact our team for a consultation.
As international litigation experts know, a naval blockade is traditionally considered an act of war. In the absence of a Security Council resolution: which will not be forthcoming due to the certainty of Russian and Chinese vetoes: the United States is acting unilaterally. It is operating without legal cover in the world’s most sensitive maritime chokepoint.
The Cost of Strategic Self-Harm
Perhaps the most baffling element of this blockade is the long-term damage to the United States’ own legal standing. For over a decade, Washington has been the primary advocate for the “rules-based international order” in the South China Sea and the Taiwan Strait.
The US has repeatedly invoked UNCLOS transit passage rights to challenge Chinese claims, arguing that the universality of these rules is the only thing preventing global anarchy at sea. The US hailed the 2016 South China Sea arbitration award as a definitive vindication of these doctrines. Every “Freedom of Navigation Operation” (FONOP) conducted by the US Navy is premised on the idea that these rules apply to everyone, everywhere, at all times.
By breaking the rule in Hormuz, the US has handed its strategic rivals a gift. China has already condemned the blockade as a violation of the freedom of navigation. From a legal standpoint, Beijing is correct. The United States has provided a ready-made legal justification for China to restrict transit through the Taiwan Strait, using the very precedent Washington just established.
For those involved in arbitration and international dispute resolution, the erosion of these norms is deeply concerning. When the world’s most powerful maritime nation decides that rules are optional, the rules don’t disappear: but their authority certainly does.
What Actually Breaks: The Credibility of International Law
International law has no standing navy to enforce its decrees. Its power is derived from three things: credibility, consistency, and the shared perception that rules apply to everyone.
In 1609, Hugo Grotius wrote Mare Liberum (The Free Sea), arguing that the sea cannot be enclosed or owned because human commerce requires it to remain open for the benefit of all. Four centuries later, that principle remains the bedrock of the global economy.
What has changed is that the very state most responsible for the modern enforcement of this principle is now the one dismantling it. The blockade may or may not achieve its short-term military objectives against Iran. However, it has already inflicted a serious, self-inflicted wound on the international legal order.
At Del Canto Chambers, we believe that the rule of law is the only stable foundation for international business and global mobility. When that foundation is shaken by unilateral action, the tremors are felt by every business, shipping line, and state that relies on the predictable application of the law.
The war may eventually end, but the legal precedent set by this blockade will outlast the current conflict. It is a reminder that the rule of law is fragile, and once broken, it is not easily mended.
For further insights into international law and how these global shifts affect your interests, you can explore our DCC News section or contact our team for a consultation.
