• Iran’s IRGC Navy warned vessels to stay at least 10 miles from US warships in the Strait of Hormuz, threatening a "firm response" including missiles and drones.
  • Clashes and gunfire reported in the waterway, with shipping traffic sharply reduced and UKMTO designating the area as high risk.
  • The escalation raises oil price volatility and disrupts global maritime flows, with energy markets on edge.

Strait of Hormuz Under Heightened Risk

Iran’s Islamic Revolutionary Guard Corps Navy issued a warning to commercial and military vessels on Thursday, ordering them to keep at least 10 nautical miles from US warships in the Strait of Hormuz, according to people familiar with the matter. The IRGC signaled it may need to "teach the Yankees a lesson" with missiles and drones if vessels cross without approval, escalating tensions that have simmered since US and Israeli strikes on Iran earlier this year.

Reports of overnight clashes and intense gunfire in the waterway have compounded the risk. The UK Maritime Trade Operations agency has called the area "high risk," and shipping traffic through the strait remains sharply reduced. "We have seen a significant drop in transits, with many vessels rerouting or anchoring," a shipping executive said, speaking on condition of anonymity.

The IRGC’s warning comes amid a broader pattern of US-Iran hostilities. Since early 2026, Iran has threatened to target ships passing through the Strait without IRGC approval, while the US has led efforts to safeguard shipping. The latest incidents test ongoing ceasefire and de-escalation efforts, with mediation by Oman and Muscat cited as potential avenues, though prospects remain uncertain.

Market and Energy Implications

The disruption has roiled global energy markets. Oil prices surged on Thursday, with Brent crude rising 2.5% to $89 per barrel, as traders priced in the risk of prolonged disruption. The Strait of Hormuz is a critical chokepoint for about 20% of global oil and LNG shipments. "Any sustained closure would have severe consequences for energy supply chains," said an energy analyst. Shipping delays and higher insurance costs are already pressuring routes, with some tankers avoiding the area entirely.

The situation remains fluid. The IRGC has warned vessels to maintain a 10-mile buffer, but without a de-escalation, the risk of direct confrontation grows. "We are monitoring closely," a US defense official said, adding that allied naval forces remain on standby. Attempts to reach Iran’s mission to the UN for comment were unsuccessful.

Correction: An earlier version of this article misstated the distance advised by the IRGC. It is 10 nautical miles, not 10 miles.