As the war with Iran escalates, shipping costs are rising sharply and traffic through the Strait of Hormuz has all but dried up — a serious shock for global energy markets.

The strait, a narrow sea lane off Iran’s coast, carries roughly a fifth of global oil consumption and large volumes of liquefied natural gas (LNG). Iran has warned it will target vessels attempting to transit the route, and ships in the wider area have already been struck. Ship-tracking platforms have shown the strait looking unusually quiet, fuelling fears of a prolonged disruption.

Those fears have pushed oil and gas prices higher, prompting major powers to call for the shipping lane to be kept open. China’s foreign ministry spokesperson Mao Ning urged all sides to halt military operations, avoid escalation and protect maritime routes to limit wider economic fallout.

Donald Trump has gone further, saying the US will guarantee the “free flow” of energy and suggesting the US Navy could escort tankers through the Gulf. He has also floated “political risk” insurance and guarantees for maritime trade — though key details remain unclear.

Analysts note that China may have the most to gain if the US ends up underwriting safe passage. China is the world’s largest crude importer and one of the biggest buyers of Iranian oil — a point highlighted by Trump’s critics, who argue the US could effectively be subsidising and protecting energy shipments bound for China. More broadly, much of Asia relies heavily on Middle Eastern oil, and China and Japan are among the biggest LNG importers, meaning any stabilisation of Hormuz routes would disproportionately benefit Asian buyers.