TEHRAN, July 12 — A decades-old legal dispute over one of the world’s most critical maritime chokepoints is simmering once more, with Iran’s claim that it could close the Strait of Hormuz drawing sharp international condemnation. The strait, a narrow passage connecting the Persian Gulf to the Gulf of Oman, is a vital artery for global oil shipments. The foundation of Iran’s position rests on its interpretation of the United Nations Convention on the Law of the Sea, a treaty Tehran signed in 1982 but has never ratified.
Iran argues that the convention grants it the right to take measures to protect its national security and environment, citing what it calls threats from U.S. sanctions and the American military presence in the region.
What UNCLOS Actually Says
The relevant sections of UNCLOS, Articles 37 through 44, define the legal framework for straits used for international navigation. These articles guarantee the right of transit passage for all ships, a principle that the vast majority of nations, including the United States, consider settled international law. Iran’s interpretation stands in direct opposition to that consensus.
The U.S. and most nations reject the notion that any single nation can unilaterally restrict transit through what they regard as an international waterway. In 2018, Iran’s Supreme Leader Ali Khamenei stated that Iran could block the strait if its oil exports were halted.
That statement signaled the seriousness with which Tehran views the issue.
A History of Resolutions
The United Nations Security Council has not been silent on the matter. Resolution 598, passed in 1987 to help end the Iran-Iraq War, explicitly called for free navigation in the region. That resolution remains on the books and is frequently cited by diplomats as a binding commitment to keeping the strait open.
If Iran were to follow through on its threat, it would almost certainly violate UNCLOS. Such an action could trigger international legal proceedings at the International Court of Justice, where the U.S. or other affected nations could seek a ruling against Tehran.
What Comes Next
For now, the situation remains one of legal posturing and political brinkmanship. Iran has not moved to close the strait, but its repeated claims to that right keep the issue alive in diplomatic circles. The U.S. administration under President Donald Trump has maintained a policy of maximum pressure on Iran, including sanctions that target its oil exports — precisely the trigger Khamenei has warned could lead to closure.
The legal question at the heart of the dispute is unlikely to be resolved soon. Until it is, the Strait of Hormuz will remain a flashpoint where international law, national security, and the global economy converge.
