FT: US limits Strait of Hormuz military escort windows for tankers

The United States has limited the times when tankers can transit the Strait of Hormuz under U.S. military air protection, as Iranian attacks on commercial shipping have intensified, according to the Financial Times.

Since May, Washington has offered air-based protection to vessels using a route along the Omani coast in the southern part of the strait. Shipowners previously received broad overnight transit windows from the U.S. Naval Cooperation and Guidance for Shipping (NCAGS).

The system was changed in early September to two specific transit windows each day, according to emails from NCAGS reviewed by the Financial Times. Vessels have been given recommended departure times to maximise U.S. military support.

“We are now providing recommended transit times that vary by day. Your vessel is not required to go during these times, but it is encouraged in order to receive the best support,” one NCAGS email said.

Another warned that “Transiting during a period of darkness has not proven to be the most secure time of day,” citing threats to commercial shipping.

The U.S. adjustment comes as Iran and the United States have stepped up attacks involving commercial vessels in and around the strategic waterway. Iran has attacked dozens of ships since the conflict began, while Tehran has also announced plans for a “restricted zone” in the strait.

The move allows Washington to concentrate limited air-defence resources during shorter periods rather than maintain protection throughout the night. Naval analyst Joshua Tallis of CNA said the change was likely “an effective means to manage the costs associated with a persistent and indefinite US defence of the southern Strait of Hormuz route”.

A maritime security adviser said concentrating resources into shorter windows would give the U.S. greater military capability to protect vessels during those periods.

Retired U.S. Vice Admiral John Miller said maintaining continuous air coverage would be difficult over a prolonged period.

“As we settle in for something that could be a process that we’re doing for a while, it’s going to be important to husband the assets in a way that allows us to be able to sustain the activity,” Miller said.

Providing air cover 24 hours a day “would be really hard to do over an extended period of time” and the United States would therefore “have to put some guidelines on it”, he added.