Britain and France agreed to begin reciprocal use of sovereign trials facilities in their respective countries and expand technical cooperation as they pursue closer coordination between their independent nuclear deterrents.
The announcement came in a joint statement published Tuesday, Nov. 10, after senior officials and military personnel met in London for the Nuclear Steering Group under the Northwood Declaration. The UK Cabinet Office jointly chaired the group alongside the Presidency of the French Republic.
The group said closer ties require a potential aggressor to assess both independent forces when considering a threat to either country’s vital interests. Officials pointed to Britain’s first participation in Operation Rummy as evidence of greater operational alignment. The UK Ministry of Defence said the Oct. 20-21 exercise paired Royal Air Force Typhoons with French Rafales in a simulated nuclear mission and used no nuclear weapons.
France’s Forward Deterrence initiative, which includes 10 European partners while leaving Paris with sole authority over any decision to use nuclear weapons, was also discussed. The group described the initiative as a complement to NATO, saying it supports security in Europe and across the Euro-Atlantic while making adversaries’ planning more difficult.
Officials cited the 2010 Teutates Treaty and EPURE, the UK-France joint testing facility, as precedents for the planned technical work. They also renewed support for international nonproliferation efforts and engagement with other nuclear weapons states. The statement named the Non-Proliferation Treaty review cycle and P5 Process as channels for that work; France took over from Britain in the process in September 2026.
