The world's maritime trade — about 80 percent of all goods moved by volume — passes through perhaps a dozen narrow waterways, none of them more than a few miles wide at the pinch. The Strait of Hormuz, between Iran and Oman, narrows to roughly 21 nautical miles and carries about a third of the world's seaborne oil. The Strait of Malacca, between Indonesia and Malaysia, funnels the trade between East Asia and the Middle East through a channel that at one point shrinks to under two miles. The Suez Canal and the Bab-el-Mandeb govern Mediterranean–Red Sea–Indian Ocean traffic; the Panama Canal stitches together the world's two largest oceans across 51 miles of locks. Block any of these for a week and global supply chains stutter; block one for a month and the world enters a recession.
Choke points are the physical geography that abstract globalization rests on. They were prized by 19th-century imperial planners — Britain seized control of Suez in 1882 and held Singapore, Gibraltar, and Aden precisely to command these gates — and they remain the spine of 21st-century naval doctrine. The US Navy spends most of its peacetime presence preserving freedom of navigation through them, an inheritance of the Pax Britannica it assumed after 1945. Conflicts that look regional — Houthi attacks on Red Sea shipping that cut Suez traffic by more than half in 2024, Iranian threats to mine Hormuz, Chinese naval exercises in the South China Sea — are also contests over the world's most consequential infrastructure. The 2021 grounding of the Ever Given in the Suez Canal, which wedged 220,000 tons of ship sideways and blocked traffic for six days, held up an estimated $9–10 billion of trade per day and stranded over 400 vessels. The vulnerability recurs in every supply-chain reform proposal; the cure is hard, because building redundant infrastructure — alternative ports, the proposed Thai Kra Canal, pipelines bypassing Hormuz, the India–Middle East–Europe rail corridor — is enormously expensive and diplomatically fraught. Geography offers no spare gates; only enforcement keeps the existing ones open.
The Russia–Ukraine war's strangulation of Black Sea grain shipping, the Houthi campaign that rerouted Asia–Europe traffic the long way around the Cape of Good Hope, Chinese live-fire drills encircling Taiwan — all are reminders that choke points are choke points only as long as someone enforces freedom of passage. The post-1945 global trade order has rested, more than on any other single thing, on the US Navy's policing of these dozen narrow waters. As Washington signals a more selective global posture and China builds a blue-water fleet of its own, whether that policing continues — and who pays for it — is one of the load-bearing assumptions of the next decade.