Strait of Hormuz closure cuts world oil supply by a fifth, sending prices soaring and revealing the waterway's critical vulnerability as a global energy chokepoint. Tanker operators halted traffic after the US and Israel attacked Iran, stranding over 800 vessels and triggering an unprecedented energy crisis. This shutdown, the most severe since the 1940s, underscores how a narrow 35-mile passage underpins global oil flows, with no viable alternative route out of the Persian Gulf. The Carter Doctrine commitment to keeping Hormuz open now faces its sternest test, exposing the geopolitical gamble of relying on this single conduit for a fifth of global oil and gas. Oil prices surged as the crisis deepened, threatening to worsen economic strains already evident in weak US jobs data.