This summer, Iran might finally have provided China a viable solution to its “Malacca Dilemma.” In the process, Beijing finds new geopolitical leverage with Washington, writes Daniel Markey.

For at least the past two decades, Chinese leaders and strategists have viewed the Strait of Malacca and the other narrow maritime passageways linking the Indian Ocean to the South China Sea as critical strategic liabilities. As of 2017, 80% of China’s maritime oil imports flowed through Malacca, a congested waterway that reaches only 1.7 miles across at its narrowest point. Passage through the strait can be slowed by shipwrecks and disrupted by terrorism or piracy. In 2003, however, Chinese president Hu Jintao famously pointed out another threat keenly felt by Beijing: that “certain powers have all along encroached on and tried to control navigation through the strait.” By “certain powers,” Hu meant the United States, which to this day holds important geopolitical leverage over China because the U.S. Pacific Fleet can threaten to squeeze China’s principal lifeline for energy and trade.

To better secure its shipping lanes, Beijing has invested in a significant expansion of its own navy, building new ships, submarines, and even a port facility and base in Djibouti at the mouth of the Red Sea. Equally important, China has diversified its energy supply portfolio to include overland suppliers in Russia and Central Asia. President Xi’s signature “Belt and Road Initiative,” is designed, at least in part, to improve China’s overland trade and transit options across continental Eurasia to the Middle East and Eastern Europe by a web of new roads, rails, and pipelines.

China cannot entirely secure or diversify its way out of trouble.