Although everyone agrees that geographically, the Strait of Hormuz is a strait, its political and legal status is much more complicated.
The United States and Iran view the Strait of Hormuz – a crucial point through which 20% of the world’s oil passes – very differently. Washington considers it an international waterway, while Tehran sees it as part of its territorial waters.
Therefore, the U.S. deems Iran's imposition of fees on ships as illegal. Similarly, President Donald Trump's blockade of the strait is a "serious violation" of Iran's sovereignty.
For any maritime law expert, it is clear that part of the issue stems from the fact that the United States and Iran exist in two different worlds regarding the international laws governing the strait. What further complicates matters is that both countries operate under a different legal framework compared to most of the rest of the world, writes The Conversation.
What Maritime Law Says
International maritime law, or the "Law of the Sea," is a set of laws, customs, and international agreements that establish the foundation for rights of access and control in the ocean. This framework operates independently of the laws of war, which are relevant to the situation in the Persian Gulf.
The United Nations Convention on the Law of the Sea, or UNCLOS, is a significant element of maritime law. Completed in 1982 and in force since 1994, the convention aims to create a stable network of zones and places - such as international straits - where everyone agrees on who and what can do. It has been ratified by 171 countries and the European Union, but, coincidentally, not by Iran, nor the United States. Iran has signed it but has not ratified it; the U.S. has not taken either of these steps.
This means that the rules to which almost every country in the world consents cannot serve as a basis for an agreement on how the U.S. and Iran should act in the strait during the current conflict.
Both Iran and the U.S. agree that, according to maritime law, Hormuz is an international strait, but not on its type. Furthermore, they do not agree on the existing relevant laws and how they apply.
How Iran Views the Strait
For Iran, Hormuz is an international strait as provided for by previous international law before UNCLOS - especially the International Court of Justice decision in the Corfu Channel case of 1949 and the Convention on Territorial Seas of 1958.
These older standards provide that foreign ships have the right of "innocent passage" through international straits. In other words, if a ship simply passes through straits without doing anything else and without affecting the security of coastal countries, it must be allowed to pass.
This grants Iran and Oman, the other country bordering the strait, the power to establish and enforce certain rules regarding passage, such as safety and environmental rules. They also have broad discretion in deciding if the passage is "innocent" and therefore not allowed. But this does not give them the right to impede innocent passage.
Contrary to the older standard, however, Tehran claims the right to "suspend" passage through its half of the strait on the grounds that that portion represents its maritime space. This constitutes a violation of the Convention on Territorial Seas of 1958, which Iran relies on for legal support, stating that when a territorial sea is also an international strait, innocent passage cannot be suspended.
The American Interpretation
For the United States, the Strait of Hormuz is an international strait requiring "transit passage," as per UNCLOS. Although the United States is not a member of UNCLOS, they argue that the updated concept of "international strait" should apply.
Classifying a waterway under the newer concept of "international strait," which requires transit passage, shifts the balance away from coastal state control in favor of free navigation.
According to this standard, countries bordering straits - like Iran and Oman in the case of Hormuz - must also allow overflight and submerged navigation of submarines. Passage must be allowed as long as it is "continuous and expeditious."
The U.S. has strongly asserted this position at sea through regular patrols for "freedom of navigation" in the Strait of Hormuz and other straits worldwide. The patrols represent a visible rejection of claims over the ocean that the U.S. deems illegal or excessive.
The fundamental argument of the U.S. is supported by renowned legal experts, such as James Kraska, a professor of international maritime law at the U.S. Naval War College, who denounces the Iranian position as "malignant" and argues that Iran must adhere to the compromises made under UNCLOS.
Custom and Exception
However, the U.S. position represents a global exception. At the same time, the United States is among the few countries - along with the United Kingdom, France, Australia, Thailand, and Papua New Guinea - that argue that "transit passage" is imposed based on custom.
In this sense, custom is established if a particular practice at sea is considered consistent and is widely agreed upon regarding its legality. If something is deemed customary law, it applies to all. The only way to prevent the application of custom is through "persistent objection," which grants a country an exemption from newly emerged standards if it has consistently been against it.
Legal experts are divided on whether transit passage is customary law - although maritime law specialists tend to say it is not.
Iran argues that even if transit passage were customary international law, Iran is in a "persistent objection," and therefore, the rule does not apply to it.
And it is true that Iran's objection has been consistent. Both Iran and Oman advocated for innocent passage and against transit passage during UNCLOS negotiations, the publication notes.
Iran reaffirmed its perspective upon signing UNCLOS in 1982. Tehran argues that since transit passage is linked to the compromises made under UNCLOS, only countries ratifying the treaty can claim the right to transit passage. Neither the U.S. nor Iran has ratified it.
Navigating Troubled Waters
The complex military situation and economic disruptions are just part of the story of the Strait of Hormuz. What lies beneath is a complicated legal situation, notes The Conversation.
Not only do the U.S. and Iran disagree on the legal status of the strait, but countries flying the flags of tankers - and therefore responsible for them - must also manage their own commitments and perspectives under maritime law.
Each country aims to avoid a legal precedent that goes against its long-term interests. However, for international law to function - to reduce conflicts and enable trade - there needs to be an agreement on existing rules and a shared commitment to uphold them.
Only then can a stable post-war status be achieved for the Strait of Hormuz. How we get there, however, requires navigating through very challenging waters, concludes the publication.
T.D.