Global oil markets are now responding to the most serious disruption to Middle East energy supply since the 1970s. Following coordinated US and Israeli military strikes on Iran on 28 February 2026, the Strait of Hormuz has effectively closed to commercial shipping, putting roughly 20 per cent of the world's daily oil supply in jeopardy. With Brent crude reaching $85.41 per barrel by 5 March and forecasters warning of $100 or beyond, governments, energy agencies and shipping insurers are all reassessing the stability of global supply chains.