Three weeks into the campaign of US and Israeli airstrikes against Iran and attention has shifted to the Strait of Hormuz and the closure of this vital waterway. The Strait of Hormuz is 39 km wide at its narrowest point, but this does not fully capture how constrained transit is. The designated shipping lanes are only about 3.7 km wide in each direction. Through these waters pass about 20 percent of global oil consumption and roughly one-third of all seaborne oil trade, much of it destined for Asian markets, particularly China, Japan and South Korea.