Rights of passage through international straits like Strait of Hormuz governed by UNCLOS but neither the U.S. Or Iran are party to the treaty

Normally, the rights of States situated along straits used for international navigation, such as Iran, and the rights of other nations to use the strait, such as the United States, are governed by the rules in UNCLOS. The treaty was adopted by a United Nations sponsored conference in 1982 after nine years of negotiation. Preceded by three failed attempts to negotiate a comprehensive multilateral oceans framework — at The Hague in 1930 and in Geneva in 1958 and 1960 — UNCLOS marks a singular achievement in world order that is second in importance only after the Charter of the United Nations.

Since its adoption, the Law of the Sea Convention has begun to fill the role envisioned by Singapore Ambassador and President of the Conference T. B. Tommy Koh as the constitution for the world’s oceans.⁴⁵ The framework forms an umbrella of global legal authority that is supplemented by some fifty additional treaties, and hundreds of codes and guidelines to form a comprehensive set of legal regimes and norms that apply throughout the oceans.

One of the principal achievements of UNCLOS was the determination of the lawful width of coastal State territorial waters, and the associated navigational regimes that apply within them. The rules governing naviga- tion are particularly important in international straits overlapped by territorial seas. In the case of U.S. and Iranian rights and duties in the Strait of Hormuz, however, the rules are much less certain because neither country is party to the omnibus treaty. The two states are among the most notorious holdouts, yet they also accept many terms of the Convention — just not necessarily the same ones. The absence of a clear and common rule- book and lack of agreement on the relevant rules that apply to the Strait of Hormuz generates regional instability.