Strait of Hormuz shipping grinds to halt as US-Iran fighting resumes

Hundreds of vessels are exposed in the Strait of Hormuz after renewed U.S.-Iran fighting and fresh attacks on tankers slowed oil and gas shipping sharply through one of the world’s most critical chokepoints. The disruption hit a waterway that carried about 20 million barrels of oil and oil products a day in 2024, roughly a quarter of global seaborne oil trade, while about 20% of global LNG trade also passed through the same narrow lane.

Few alternatives exist if the strait is disrupted, even though the U.S. Energy Information Administration puts pipeline capacity that could reroute some crude at 3.5 million to 5.5 million barrels a day. The International Energy Agency warns that even a short-lived interruption would have significant effects on oil markets, including shipping insurance, freight rates, and the costs that eventually reach refineries, power plants, and consumers.

The U.N. International Maritime Organization is monitoring more than 20,000 seafarers in the region, including around 6,000 stranded on hundreds of ships in the Persian Gulf after the renewed attacks in early July. In March, at least four seafarers were killed and three were severely injured in an attack on a vessel in the strait.

The Joint Maritime Information Center raised the threat level in the Strait of Hormuz to “severe” after the latest attacks, with deliberate hostile action likely under current conditions. Iran’s joint military command warned that tankers must use Tehran’s approved routes or face a “forceful response.” On July 7, a Qatari LNG tanker was at risk of exploding after a projectile strike, alongside a damaged Saudi crude tanker.

The present crisis echoes the Tanker War of the 1980s, the best-known earlier period of sustained attacks on merchant shipping in and around the strait during the Iran-Iraq War. The United States has protected shipping there before, and that precedent shapes Washington’s response as the June 15 framework between U.S. and Iranian officials to end their war and reopen the strait gives way to renewed confrontation.