Iran’s closure of the Strait of Hormuz and efforts to extract payments for safe passage — plus, more recently, the Houthis’ move to attack Saudi shipping through the Bab el-Mandeb Strait — have highlighted the risks of maritime chokepoints to global shipping and raised questions about the future for freedom of navigation. For the engineers who dominate today’s party-state, maritime chokepoints reverse the Venturi effect: Instead of accelerating flow through a narrow passage, military threats slow or halt commercial and naval traffic, magnifying gray-zone coercion and wartime costs.The Strait of Hormuz’s leverage stems from Gulf energy exports to Asia, much of which transits through the Malacca Strait. Since 2013, Chinese leader Xi Jinping has sought to reduce China’s reliance on Malacca through diversified supply routes, larger strategic reserves, renewable energy, and overland corridors. Yet, overland alternatives cannot fully replace maritime transport, leaving Beijing to hedge across multiple networks. Iran’s closure of the Strait of Hormuz and efforts to extract payments for safe passage — plus, more recently, the Houthis’ move to attack Saudi shipping through the Bab el-Mandeb Strait — have highlighted the risks of maritime chokepoints to global shipping and raised questions about the future for freedom of navigation.