Speaking to a room of law enforcement officers in Garden City, New York on Friday, President Trump said that once the war with Iran is finished he will be “declaring the Hormuz Strait a territory of the United States.” Then he said the part that matters: “Essentially, that’s what it is. We have the blockade. No ships get through unless we want them to.”

That second sentence tells you what the first one is. This is not a legal claim being prepared somewhere in the State Department. It is a description of the blockade with a word attached to it that the blockade does not earn.

Iranian military spokesman Mohammad Akraminia issued an explicit threat this week that countries following the United States in imposing sanctions on Tehran would face difficulties transiting the Strait of Hormuz. The statement, reported by the state-aligned Tasnim news agency, dropped any residual pretense of Iranian restraint in the waterway. Akraminia added that the enemy had recognized it could not break the resolve of Iranian forces and would ultimately be compelled to accept a ceasefire on Tehran’s terms.

Three small islands sit near the entrance of the Strait of Hormuz. Abu Musa belongs to the emirate of Sharjah. Greater Tunb and Lesser Tunb belonged to Ras al-Khaimah. In November 1971, two days before the British protectorate over the Trucial States expired and three days before the United Arab Emirates came into formal existence as an independent nation, Iranian forces occupied all three. Greater Tunb was taken by force, killing several Ras al-Khaimah police officers who attempted to resist. Abu Musa was occupied under a memorandum of understanding with Sharjah that Iran has since interpreted in ways that effectively amount to full occupation. The UAE has never accepted any of this. The dispute is over fifty years old and shows no sign of resolution.

The Strait of Hormuz is a strait used for international navigation overlapping with the territorial waters of Iran and Oman. Under the United Nations Convention on the Law of the Sea, such straits are subject to the right of transit passage — a legal regime that grants all ships and aircraft the right to continuous and expeditious transit, and that limits the ability of coastal states to interfere with that transit. Iran has not ratified UNCLOS. It does not accept the transit passage framework. This legal disagreement is not merely academic. It is the normative foundation on which Iran’s claimed right to close or restrict the strait rests, and the normative foundation that every other party invokes to deny Iran that right.