Tanker traffic in the world’s most critical energy chokepoint, the Strait of Hormuz, through which 20 per cent of the world’s oil supply is transported, has effectively halted. Brent crude surged as much as 13 per cent intraday to $82 a barrel. UBS analysts warn Brent could hit US$120 a barrel if the Strait remains blocked; and Barclays estimates a three-to-four week squeeze could push prices above US$100. On Monday, Qatar’s national LNG company, 20 per cent of global supply, halted production and Saudi Arabia shut its biggest domestic oil refinery after a drone strike.