Narrow passages of strategic importance through which sea-bound traffic must pass. Examples include the Panama Canal and the Suez Canal. Control or disruption of these chokepoints can have significant global economic and security consequences.

Areas of the Earth that are not owned by any single state and are accessible to all nations, such as the high seas, the atmosphere, and outer space. Their governance often relies on international cooperation and agreements.

A legal regime under the United Nations Convention on the Law of the Sea (UNCLOS) that allows ships and aircraft to pass through international straits. It guarantees freedom of navigation and overflight for the purpose of continuous and expeditious transit.