Three of Britain's four nuclear submarines put to sea in 'unusual' move as the Foreign Office warns of 'sudden escalation'
Britain deployed three of its four Vanguard-class nuclear submarines simultaneously at sea, a move defence sources describe as occurring in "unusual circumstances" with no full public explanation.
Three Vanguard-class submarines — HMS Vanguard, HMS Vigilant and HMS Vengeance — are at sea simultaneously for the first time in at least seven years, as the Foreign Office warns Britons that "the risk of sudden escalation is high" in the Middle East. At least one vessel is on routine nuclear patrol, a second is ready to rotate onto patrol, and HMS Vigilant has departed for trials after an extended maintenance period. The fourth boat, HMS Victorious, remains at Devonport undergoing maintenance.
A source insisted the deployment is "not related to any direct threat" and called it a "coincidence," though adversaries and NATO allies will take note.
The news follows RAF jets joining France in a "simulated nuclear strike" war games exercise for the first time just days ago.
Submariners have endured patrols exceeding 200 days — one crew came home after 205 days at sea in 2026, a record — because previously only two submarines were fit to sail.
