Strategic Chokepoints and Naval Power

A maritime chokepoint is a narrow passage along a heavily used sea route where geography, rather than any single navy, dictates who can move goods and warships between two larger bodies of water. The Strait of Hormuz, between Iran and the Musandam peninsula of Oman, narrows to roughly 21 nautical miles (about 39 km) at its tightest point, yet the U.S. Energy Information Administration has repeatedly identified it as the world's single most important oil chokepoint, with around a fifth of global petroleum liquids consumption passing through it. Iran has periodically threatened to close the strait in response to sanctions or military pressure, most visibly during the 1980s "Tanker War" phase of the Iran-Iraq War and again amid tensions following the 2018 U.S. withdrawal from the Iran nuclear deal, though a full closure would also cut off Iran's own export routes, a mutual dependency that has so far restrained any actual blockade. Alfred Thayer Mahan's The Influence of Sea Power upon History, 1660-1783 (1890) first systematized the idea that command of such narrow seas, not merely open-ocean battle fleets, determines a great power's ability to project force and protect commerce, a framework still invoked in modern discussions of Hormuz, the South China Sea, and the Arctic's opening shipping lanes.