Can the Strait of Hormuz Be Owned? Trump, Tehran, and the Law of Transit Passage

Speaking at a campaign event in Garden City, Long Island on August 14, President Trump told an audience of law enforcement officers that "after we finish defeating Iran, which is being very badly defeated, pretty soon I'll be declaring the Hormuz Strait a territory of the United States." He added, "Essentially, that's what it is. We have the blockade. No ships get through unless we want them to."

Iran's Deputy Foreign Minister Kazem Gharibabadi responded on X within hours. The strait "cannot be seized by tweet, nor by aircraft carrier, nor by issuing an order, nor by an election speech," he wrote, adding that it "has been Iranian, is Iranian, and will remain Iranian."

Beneath the exchange sits a question that is genuinely interesting as a matter of law and that neither statement addresses. What would it actually mean to own a strait, and would owning it deliver the control that both parties appear to assume it confers?

The answer is more counterintuitive than either position suggests, and it matters for anyone routing vessels through the region.

Whose Water Is It

Start with geography, because it determines everything downstream.

The Strait of Hormuz is 21 nautical miles wide at its narrowest point. Since Iran extended its territorial sea to 12 nautical miles in 1959 and Oman did the same by decree in 1972, the entire strait is covered by the territorial seas of the two bordering states. There is no high seas corridor running through the middle. A vessel transiting Hormuz is in somebody's territorial waters for the whole passage.

Which somebody matters. The Traffic Separation Scheme recognized by the IMO places the inbound lane close to the Omani coastline and the outbound lane toward the Sea of Oman, with the result that the majority of the established shipping lanes run through Omani territorial waters rather than Iranian ones. The northern corridor through Iranian waters has historically attracted little commercial traffic.

That produces the first difficulty with any claim to the strait as territory. The waters are not unclaimed. They belong, in the sense that territorial seas belong to anyone, to two states, only one of which is a party to the current conflict. Oman is not at war with the United States.

The Bargain That Created the Modern Regime

The second difficulty is more fundamental and requires understanding why the law is structured as it is.

Before UNCLOS, the accepted territorial sea was three nautical miles. Extending it to twelve, which coastal states wanted, would have placed roughly 138 additional straits under the jurisdiction of one or more coastal states, converting corridors that had been high seas into national waters.

The maritime powers, the United States prominent among them, refused to accept that unless something was given in return. What they demanded, and received, was a passage regime through those straits stronger than the innocent passage that ordinarily applies in territorial waters.

That trade is the foundation of Part III of UNCLOS, Articles 34 through 45. Coastal states got the twelve mile territorial sea. Shipping got transit passage.

Article 38 provides that all ships and aircraft enjoy the right of transit passage, defined in Article 38(2) as the exercise of freedom of navigation and overflight solely for the purpose of continuous and expeditious transit. Article 44 provides that states bordering straits shall not hamper transit passage and that there shall be no suspension of it.

Article 42 permits bordering states to establish sea lanes and traffic separation schemes, but confines their regulatory authority to matters of safety, pollution control, and the prevention of fishing. Article 39 requires transiting vessels to refrain from any threat or use of force against the bordering state.

The structural logic, as one analysis put it, is that when much of global trade depends on a narrow corridor, the bordering states are not permitted to use that corridor as leverage.

What Sovereignty Over a Strait Actually Gives You

Here is the point that both the American and Iranian positions elide.

Under Article 34, the bordering states retain sovereignty over the waters forming a strait. But the exercise of that sovereignty is expressly subject to Part III. Sovereignty over strait waters is not ownership in the sense of exclusive control. It is title encumbered by an international right of passage that the sovereign cannot suspend.

The correct question is therefore not who owns Hormuz. It is how sovereignty and transit rights coexist there.

Follow that through and the practical implication is striking. If the United States somehow acquired sovereignty over the strait, it would acquire the same encumbered title that Iran and Oman currently hold. It would inherit the obligation not to hamper transit passage and not to suspend it. Sovereignty would not deliver the power to decide which ships get through, because that power does not exist within the transit passage regime regardless of who holds the sovereignty.

The same logic constrains Iran. The assertion that the strait will only be closed and opened under Iranian command describes a power that the transit passage regime does not grant to the sovereign.

Owning a strait, in the sense that international law recognizes ownership of strait waters, does not include the right to close it. That is the entire point of the regime.

The Competing Legal Positions

The picture is complicated by ratification status, and each state's position deserves accurate statement.

Iran signed UNCLOS but has not ratified it. Its position is that transit passage binds only parties to the Convention, and that it need grant no more than innocent passage, which unlike transit passage can be suspended. It also maintains that foreign warships must coordinate access with Iranian authorities. Iran's 1993 Law of Marine Areas in the Persian Gulf and Oman Sea permits suspension of foreign vessel passage in its territorial waters and requires prior authorization for warships, submarines, and vessels carrying materials dangerous or harmful to the environment, a category capable of encompassing loaded oil tankers.

The United States has also not ratified UNCLOS. Its position is that transit passage has become a firm right of all states under customary international law, binding on parties and non-parties alike. The U.S. Navy has operated a freedom of navigation program since 1979 asserting exactly that.

Oman has ratified UNCLOS, but appended statements affirming full sovereignty over its territorial sea and reserving a right to require prior permission for warship passage. UNCLOS does not permit reservations of that kind. In practice Oman generally adheres to the transit passage regime.

One consequence of the geography deserves emphasis. Because most of the established shipping lanes lie in Omani waters, and Oman is undoubtedly bound to permit transit passage there as a party to the Convention, interference with passage through Omani waters raises questions of Omani sovereignty independent of any Iranian claim.

There is also a point about non-discrimination. The right of passage must not be subjected to discriminatory considerations, which is difficult to reconcile with any regime under which some vessels are permitted and others are not according to their nationality or their operator's political alignment.

Blockade Is a Different Question

The second half of the President's remark, that the United States has the blockade and no ships get through unless it wants them to, describes something legally distinct from a territorial claim, and conflating the two obscures both.

A naval blockade during armed conflict is governed by the law of naval warfare rather than by the law of the sea. Blockade is a recognized belligerent right, but it carries its own conditions. It must be declared and notified. It must be effective. It must be applied impartially to the vessels of all states. And it may not bar access to the ports and coasts of neutral states.

That last condition is the significant one here. Oman is not a belligerent. A blockade that prevented access to Omani ports or Omani coasts would exceed what the law of blockade permits, whatever its position with respect to Iran.

The practical distinction matters for operators. A belligerent right exists only during armed conflict and ends with it. A territorial claim, if it were valid, would persist. The two produce very different answers to the question of what happens to transit rights when the fighting stops.

Acquisition of Territory

One further point completes the framework. The acquisition of territory by force has been prohibited since the UN Charter entered into force in 1945. Article 2(4) requires all members to refrain from the threat or use of force against the territorial integrity or political independence of any state.

The doctrine that title passes to the victor, sometimes expressed as the principle that to the victor belong the spoils, was the pre-Charter position. It is not the current one, and the change is among the more settled propositions in modern international law.

What This Means for Operators

Setting the legal debate aside, several things follow for anyone with vessels in or near the region.

The legal framework is not currently what determines transit. Traffic through the strait is running at roughly 17 percent of the pre-conflict average, with 151 vessels recorded in a recent seven day period and 56 reports of damage to vessels since hostilities began on February 28. Whatever the correct legal analysis, the operative constraint on the water is military and commercial rather than juridical.

Watch which corridor you are in. The distinction between the established IMO traffic separation scheme lanes, which lie largely in Omani waters, and the northern corridor through Iranian waters, carries different practical and legal exposure. Iranian authorities have previously rejected an Omani proposed corridor and asserted that vessels may transit only along Iran-approved lanes while maintaining communication with the IRGC Navy.

Distinguish legal position from operational reality in your risk assessment. A vessel enjoys a right of transit passage under the framework the United States and most maritime states recognize. That right does not stop a projectile. Charter party war risk clauses, CONWARTIME obligations, and master's authority to refuse orders into unreasonable danger operate independently of who is legally correct about transit rights.

Expect the legal question to matter later. When the fighting ends, the basis on which passage is permitted or restricted will determine a great deal about routing, insurance, and cost. Whether transit through Hormuz is treated as a right exercisable without permission or as a privilege granted by whoever controls the water is the difference between a normal trade lane and a tolled one.

The Bottom Line

The exchange between Washington and Tehran is framed as a dispute about who owns the Strait of Hormuz. As a matter of law it is not clear that the question means what either party takes it to mean.

Sovereignty over the waters of an international strait is real, but it is title subject to a passage right that the sovereign is not permitted to suspend. That constraint was the price the coastal states paid for a twelve mile territorial sea, and the United States was among its principal architects.

If the American position on transit passage is correct, and it has been the consistent American position for over four decades, then acquiring the strait would confer no authority to close it. If the Iranian position is correct, that a coastal state may suspend passage at will, then the strait can be closed by whoever holds the coastline, and the argument about which flag flies over it is an argument about which state exercises a power that shipping has spent fifty years insisting does not exist.

Both propositions cannot be right. Operators routing through the region have a considerable interest in which one prevails.