Traffic through the Strait of Hormuz ground to a near halt on Thursday after the US conducted strikes on Iran for a second consecutive day, unraveling a fragile ceasefire that had held for weeks. The waterway, which carries roughly 20% of global oil supply, saw commercial vessels anchor or divert as insurers raised war-risk premiums and charterers paused loadings.

Oil benchmarks jumped in early Asian trading, with Brent crude climbing above $72 a barrel on supply disruption fears. Tanker rates for Very Large Crude Carriers on the Middle East-to-Asia route surged 15% as owners factored in longer voyage times and heightened security costs. The Strait's closure history — including the 1980s Tanker War and 2019 attacks — suggests even brief interruptions ripple through global energy markets for weeks.

The escalation follows Israeli strikes on Iranian military sites last weekend and Tehran's restrained response, which had calmed markets. Thursday's US action, reportedly targeting missile production facilities, signals Washington's willingness to degrade Iranian capabilities directly rather than through proxies. Shipping executives report vessels holding at Fujairah and Khor Fakkan anchorages awaiting clarity.

Markets now price a sustained risk premium: each day the Strait operates below capacity tightens physical crude availability, particularly for Asian refiners dependent on Middle East grades. The critical variable is whether Iran retaliates against shipping or energy infrastructure, which would transform a tactical disruption into a strategic supply crisis.