The palaces on this stretch of water were paid for by a rent extracted from geography. Venice sat where the Levant trade entered Europe, taxed what passed, and converted the proceeds into a navy that protected the arrangement. For roughly four centuries this worked better than almost any other business model available to a European state. Then it stopped working, and the reasons it stopped are directly relevant to every state whose strategic position rests on a strait.

The Strait of Hormuz has a sister chokepoint at the other end of the Arabian Peninsula. Bab-el-Mandeb, the narrow passage between Yemen and Djibouti that connects the Red Sea to the Gulf of Aden, carries the maritime traffic of the Suez Canal route — container ships, bulk carriers, tankers moving between Europe and Asia, and LNG vessels serving European regasification terminals. When Houthi forces in Yemen began attacking commercial shipping in the Red Sea in late 2023, they demonstrated that Iran’s sphere of proxy influence could threaten two of the world’s most critical maritime corridors simultaneously.

The Strait of Hormuz is 90 miles long and between 21 and 55 miles wide. The navigable channel — the portion deep enough for laden very large crude carriers and the other substantial vessels that transit it — is much narrower. Two traffic separation lanes, each approximately two miles wide, handle the inbound and outbound commercial traffic, separated by a two-mile buffer zone. The effective transit corridor for a laden supertanker is therefore something on the order of two miles across, within a strait that appears much wider on maps but that shallow water, islands, and navigational hazards reduce to a constrained passage at the critical point.