The closure of an international strait by a neighboring state during an armed conflict raises legal questions regarding the legitimacy of such actions within the framework of international law. The article reflects on the principles set forth by international treaties, customary rules, judicial precedents, and regulations governing armed conflicts at sea. Iran's announcement in early March 2026, following American and Israeli strikes on February 28, threatening maritime navigation and preventing vessels from passing through the Strait of Hormuz, presents a practical test of the legal coherence surrounding this issue.

A legal analysis indicates that despite various potential legal frameworks that could be invoked, there is no current international legal framework that authorizes the comprehensive closure of the strait. The issue revolves around the treaty system that governs navigation through straits used for international passage. The third part of the United Nations Convention on the Law of the Sea establishes the right of innocent passage through these straits. Article 38 confirms that all ships and aircraft are entitled to this right for the purpose of continuous and expeditious transit, while Article 44 makes it clear that transit passage cannot be suspended, and Article 42 further supports this by outlining navigational rights through straits used for international navigation.

Given the strategic significance of the Strait of Hormuz for global maritime commerce and security, any attempt by Iran to enforce such a closure could not only violate international norms but also exacerbate tensions in an already delicate geopolitical environment. The implications of this situation extend beyond legal debates, potentially affecting international shipping routes, regional stability, and U.S. and allied military interests, as well as provoking responses from other countries reliant on the strategic passage.