Chevron Chairman and CEO Mike Wirth has warned that the closure of the Hormuz Strait, caused by the ongoing conflict between Iran and the United States-Israel alliance, is triggering a real shortage in global oil supply. Speaking at a Milken Institute discussion on Monday, Wirth said that with 20 percent of the world’s oil shipments halted, demand will have to decline to match tightening supply, leading to an economic slowdown that will first hit Asia.

Wirth explained that Asia’s heavy dependence on Gulf oil production and refining makes it the most vulnerable region, followed by Europe. He noted that commercial surpluses, shadow fleet tankers, and strategic reserves are nearly exhausted. The United States, as a net exporter of crude oil, will be less affected initially but will eventually feel the impact as well. The last Gulf shipment is currently being unloaded at Long Beach port in California.

The Chevron chief compared the potential scale of the disruption to the oil crises of the 1970s. The report also noted that U.S.-based Spirit Airlines has ceased operations due to soaring jet fuel prices linked to the supply disruption.