The Strait of Hormuz exists in the eye of the beholder, with the US and Iran having different views on its political and legal status.
The strait is a choke point through which 20% of the world's oil passes, and its legal status is complicated by the fact that the US and Iran have different interpretations of international law.
The US sees the Strait of Hormuz as an international waterway, while Iran considers it part of its territorial waters, which gives it the right to charge tolls to ships passing through.
The US has also imposed a blockade on the passage, which Iran sees as a grave violation of its sovereignty.
Both countries are living in different worlds when it comes to the international laws governing the strait, and the situation is further complicated by the fact that neither country has ratified the United Nations Convention on the Law of the Sea (UNCLOS).
The law of the sea is a network of international laws, customs, and agreements that set out the foundation for rights of access and control in the ocean.
The UNCLOS aims to create a stable set of zones and places where everyone agrees on who can do what, but it has been ratified by 171 countries and the European Union, but not Iran or the US.
The US and Iran agree that the Strait of Hormuz is an international strait, but they disagree on what kind of international strait it is and the relevant laws that exist.
The US argues that the strait requires 'transit passage', which means that countries bordering the strait must allow overflight and submarines below the surface, while Iran claims the right to 'suspend' passage through its half of the strait.
The situation is further complicated by the fact that the US is a global outlier in arguing that 'transit passage' is required by custom, and Iran argues that it is a 'persistent objector' to this rule.
The complex military situation and economic disruption are only part of the story of the Strait of Hormuz, and what lies beneath is a complicated legal situation that requires an agreement about what rules exist and a shared commitment to abide by them.
