The international foreign policy establishment has a comfortable obsession. Whenever tensions flare in the Persian Gulf, a familiar parade of maritime lawyers and think-tank scholars emerges to debate the 1982 United Nations Convention on the Law of the Sea (UNCLOS). They obsess over "transit passage" versus "innocent passage." They write long, dry papers about whether Iran is bound by a treaty it signed but never ratified.
It is a beautiful, intellectual distraction. And it is completely wrong.
The legal debate over the Strait of Hormuz is not just a sideshow; it is an active intellectual trap. While Washington and Tehran trade barbs over the legal definition of international straits, they are playing a game of chicken where the rules of engagement are written in physical force, not treaty ink. The consensus view—that resolving the legal ambiguity of UNCLOS would bring stability—misses the entire point of modern gray-zone warfare.
The crisis in the Strait of Hormuz is not a legal dispute. It is a calculated, asymmetric siege where international law is used as a weapon, not a shield.
The Lazy Consensus: The UNCLOS Trap
The standard narrative, parroted by major foreign policy outlets, goes like this: Under UNCLOS, the Strait of Hormuz is an international strait where foreign vessels enjoy the right of transit passage. This means ships—including warships—can pass through quickly and continuously without coastal state interference. Iran, however, argues that because it never ratified UNCLOS, only the older 1958 Geneva Convention on the Territorial Sea applies. Under those rules, foreign ships only get innocent passage, which allows Iran to suspend transit if it deems the cargo or mission "prejudicial" to its peace and security.
This is the legal framing. It is neat, academic, and entirely irrelevant.
Here is what the analysts miss: Iran does not intercept oil tankers because it has a differing interpretation of Article 38 of UNCLOS. Iran intercepts tankers because it works.
I have watched maritime security experts spend decades advising shipping conglomerates and governments, pouring millions of dollars into compliance and legal defenses. They brief captains on the exact coordinates of territorial waters. They draft meticulous legal responses to Iranian boarding parties.
It is a waste of paper. When the Islamic Revolutionary Guard Corps Navy (IRGCN) pulls alongside a commercial vessel in fast attack craft, they are not carrying law books. They are carrying rocket-propelled grenades.
The legal ambiguity is not a loophole Iran is trying to exploit; it is a smoke screen they use to justify actions dictated entirely by geopolitical leverage.
The Reality of Asymmetric Leverage
Let’s look at the actual mechanics of the strait. The Strait of Hormuz is a narrow choke point. At its narrowest, the shipping lanes consist of two-mile-wide channels for inbound and outbound traffic, separated by a two-mile-wide buffer zone.
[ Oman Territorial Waters ] <--- Shipping Lane (Inbound) ---> [ 2-Mile Buffer ] <--- Shipping Lane (Outbound) ---> [ Iran Territorial Waters ]
Because of the geography, almost all deep-draft tankers must pass through the territorial waters of Oman and Iran.
If we look at the actual behavior of the IRGCN, their actions have nothing to do with maritime law and everything to do with economic retaliation.
- Exhibit A: In 2019, Iran seized the British-flagged tanker Stena Impero. The official excuse? A minor maritime collision with an Iranian fishing boat. The actual reason? Gibraltar authorities had seized an Iranian tanker, the Adrian Darya 1, a few weeks prior.
- Exhibit B: In 2023, Iran seized the Advantage Sweet, a Marshall Islands-flagged tanker. The legal pretext? A technical dispute over a collision. The real reason? The United States had recently confiscated Iranian crude oil from another vessel, the Suez Rajan.
This is not a legal disagreement. It is crude, transactional hostage-taking.
By treating this as a legal dispute, the West plays directly into Tehran’s hands. When the U.S. Navy responds by citing international law, it signals that it is willing to play a game governed by rules. Iran is playing a game governed by pain thresholds.
Why the "Freedom of Navigation" Mission is Failing
For decades, the United States has maintained the Fifth Fleet in Bahrain to guarantee the free flow of commerce through the strait. The conventional wisdom is that a massive naval presence is the only thing keeping the global economy afloat.
But look at the cost-to-benefit ratio.
The U.S. deploys billion-dollar guided-missile destroyers to escort commercial tankers. Iran deters them using $50,000 fast-attack craft, low-cost loitering munitions, and naval mines that cost less than a decent used car.
This is the definition of asymmetric disadvantage.
+-----------------------------------+-----------------------------------+
| U.S. Navy Assets | Iranian Asymmetric Assets |
+-----------------------------------+-----------------------------------+
| Arleigh Burke Destroyer: $2B+ | Fast Attack Craft: $50,000 |
| High operating & maintenance cost | Mass-produced loitering munitions |
| Rigid, rules-of-engagement bound | Highly flexible, deniable tactics |
+-----------------------------------+-----------------------------------+
Every time a U.S. destroyer is forced to maneuver around a swarm of speedboats, Iran wins the psychological battle. They demonstrate to the world that the world's premier naval superpower is constrained by the very rules it seeks to enforce, while Iran operates with complete tactical freedom.
The truth nobody wants to admit is that the presence of Western warships in the Gulf does not deter Iranian aggression; it provides them with higher-value targets for gray-zone provocation. Iran knows the U.S. does not want to spark a regional war over a seized tanker. Therefore, Iran can push the envelope right up to the line of kinetic conflict, confident that the West's legalistic framework will prevent a decisive response.
The Double-Edged Sword of Maritime Insurance
If you want to understand the real choke point of the Strait of Hormuz, stop looking at naval charts and start looking at London.
The Joint War Committee (JWC) of the Lloyd’s Market Association designates the waters of the Persian Gulf and the Gulf of Oman as a high-risk area. When tensions rise, insurance premiums for tankers transiting the strait skyrocket.
This is Iran's real weapon. They do not need to physically sink a single ship to close the Strait of Hormuz. They only need to raise the risk profile to the point where maritime underwriters refuse to insure the vessels.
Imagine a scenario where the IRGCN conducts three highly publicized drone strikes on tankers in a single week. No ships are sunk, and no lives are lost. However, insurance rates jump by 500%.
Suddenly, shipping crude through the strait becomes economically unviable for commercial operators. The strait is closed not by a physical blockade, but by a financial one.
This is the genius of the Iranian strategy. They have realized that the global shipping industry is incredibly risk-averse and highly sensitive to insurance costs. By maintaining a constant baseline of low-level threat, they hold a knife to the jugular of the global economy without ever having to fire a shot at a U.S. warship.
Stop Citing UNCLOS. Do This Instead.
The current strategy of deploying more warships and issuing stern legal statements is a proven failure. It has not stopped the harassment of shipping, and it will not stop it in the future.
If the West wants to break Iran's leverage over the Strait of Hormuz, it must abandon the legalistic illusion and change the economic calculus.
First, stop treating every tanker seizure as a maritime law violation. Treat it as an act of state-sponsored piracy and respond in kind. If Iran seizes a tanker, the international community should immediately freeze assets of equal value belonging to the Iranian state or its proxies. Do not litigate it in international courts for five years. Hit their balance sheet within forty-eight hours.
Second, the shipping industry must diversify away from the strait entirely. This means massive, sustained investment in overland pipelines that bypass the choke point altogether, such as Saudi Arabia’s East-West Pipeline and the Habshan–Fujairah pipeline in the UAE.
Yes, building and expanding pipeline infrastructure is incredibly expensive. Yes, it is logistically difficult. But it is far cheaper than maintaining a permanent, multi-carrier strike group presence in the Gulf to defend a legal principle that one side does not even recognize.
Until the West stops hiding behind the vague clauses of a treaty that has no teeth, Iran will continue to use the Strait of Hormuz as its personal geopolitical lever. The law will not save the tankers. Only a hard, unsentimental recalculation of economic and physical power will.
