The United States has restricted the hours during which it provides military protection specifically air protection to commercial tankers sailing through the Strait of Hormuz, after a surge in Iranian attacks on ships using the strategic waterway, according to a Financial Times report.
The US has provided air-based protection since May to vessels using a route along the Omani coast on the southern side of the strait, allowing some oil shipments to continue despite Iranian attacks. Under the arrangement, shipowners first sought clearance from the US naval coordination centre, known as Naval Cooperation and Guidance for Shipping (NCAGS), which provided vessels with coordinates and transit windows during which US aircraft would offer protection.
But the FT, citing emails sent by NCAGS to maritime advisers, reported that the broad overnight windows were reduced around the start of September to two specified transit slots each day. Ships were encouraged to begin their journeys at designated times to receive the best available US military support.
US Central Command, which oversees American military operations in the Middle East, declined to elaborate on the messages, saying the NCAGS communications spoke for themselves. The change came as attacks on commercial shipping intensified. Iran said on Wednesday that it had targeted two US vessels and eight oil tankers in retaliation for US strikes on five Iranian tankers.
The US military said those strikes followed an attack by Iran’s Islamic Revolutionary Guard Corps on an American warship with ballistic missiles. UK Maritime Trade Operations also reported further Iranian attacks on tankers near Dubai and Iraq. More than 70 commercial vessels have been attacked since the conflict began on February 28, according to FT.
The southern route has become particularly vulnerable to Iranian surveillance. The IRGC has used small patrol boats to detect merchant ships travelling along the Omani side, many of which have traditionally sailed at night with lights and GPS signals switched off. US support is now being concentrated into shorter windows rather than covering much of the night.
Joshua Tallis, a naval analyst at US security research organisation CNA, told the FT that the move could help Washington manage the cost of maintaining a potentially prolonged military presence around the southern route. Tallis estimated that operating an advanced US military aircraft can cost between $25,000 and $75,000 an hour.
A maritime security adviser working with ships in the Gulf told the FT that concentrating US aircraft and other resources into shorter periods could allow Washington to provide stronger protection when vessels are transiting. A commercial ship travelling at slow to moderate speed takes about seven hours to cross the strait, meaning the restricted protection windows could require operators to carefully plan their movements.
Iran has also announced plans for a “restricted zone” in the Strait of Hormuz. Mohsen Rezaei, head of the country’s Supreme National Security Council, said the zone would extend from the US naval blockade towards the strait and into the Persian Gulf. Tehran said ships entering the zone could face unspecified “sanctions”.
At the same time, Iran and Oman have agreed on details of new entry and exit routes for vessels transiting the Strait of Hormuz, with Iranian officials saying the two countries will brief other Gulf states on the arrangement at a regional meeting in Muscat on Monday.
However, shipbroker Clarksons does not expect disruption to shipping through the strait to ease until at least the second half of 2027, according to the FT. Retired US Vice Admiral John Miller, who previously commanded American naval forces in the Middle East, said the US would need to conserve its military resources if the protection mission continued for an extended period. Providing air cover around the clock would be difficult to sustain indefinitely, Miller told the FT, making some form of scheduling necessary.
