Britain deployed Royal Marine Commandos and Royal Air Force personnel to Jan Mayen alongside Norwegian and US forces to test NATO’s ability to operate in the High North. Operation Atlantic City ran from 26 August to 4 September 2026 and formed part of Arctic Sentry, the alliance’s enhanced vigilance activity in the region.
Jan Mayen lies in an isolated part of the Norwegian Sea, roughly 620 miles from mainland Norway. Its position north of the Greenland-Iceland-UK gap places it near waters that the Ministry of Defence described as vital to the security of northern Europe and the wider Euro-Atlantic area.
Personnel from LXX Squadron, Royal Air Force, and detachments from the UK Commando Force worked with the Royal Norwegian Navy, Norwegian Home Guard and US Marine Corps units. The forces integrated sensor and communications systems to improve NATO’s preparedness for potential threats.
Defence Secretary Wes Streeting said: “The High North is vital to the security of the UK and our NATO Allies. This operation demonstrates the strength of our partnership with Norway and the United States, and the ability of our Armed Forces to operate together in even the most demanding Arctic conditions.”
Streeting added: “It is a clear signal of our enduring commitment to NATO security and to defending our shared interests in the High North.” The ministry said Britain’s participation reflected its commitment to collective security and its capacity to adapt to the operational demands of the Arctic.
Operation Atlantic City ran concurrently with naval manoeuvres conducted under Operation Northern Viking 26. The timing allowed the trilateral force to maximise overlapping maritime and sensing resources across the European theatre while supporting wider Arctic Sentry activities.
The deployment built on similar Allied training conducted around Jan Mayen in 2025. It gave UK forces practical experience in maritime operations, surveillance, movement, survival and joint activity in some of the world’s most difficult weather conditions.
Military operations in the High North require forces to manage long distances, extreme weather, limited infrastructure and rapidly changing conditions. The deployment tested their ability to operate through those constraints while contributing to NATO’s deterrence posture in the Arctic.