France and UK agree to improve joint conventional warfighting capabilities under Lancaster House 2.0

Paratroopers of the French Army's 8th Marine Infantry Parachute Regiment landing in Viitna, Estonia, on 20 May 2023 during Exercise ‘Spring Storm' to reinforce the Baltic country and the UK-led NATO enhanced Forward Presence battlegroup deployed there. (Janes/Nicholas Fiorenza)

During a state visit to the United Kingdom on 10 July, French President Emmanuel Macron agreed with UK Prime Minister Keir Starmer to improve their countries' joint conventional warfighting capabilities under the Lancaster House 2.0 Declaration on Modernising UK-French Defence and Security Cooperation.

The declaration stated the France-UK intent to “[l]aunch the Combined Joint Force [CJF], overhauling the existing Combined Joint Expeditionary Force to refocus it on the Euro-Atlantic and warfighting at scale to deter, placing it on an operational footing for the first time”. The declared CJF capacity will be increased up to five times to ensure the ability to plan and command a combined corps capability that can provide the land component of a broader joint force combining all military functions as part of NATO or bilaterally. The CJF will be structured to facilitate the deployment of a force fully interoperable with NATO and available as its strategic reserve as “a critical step towards the UK and France providing two fully interoperable strategic reserve corps to NATO, enabled by the CJF”.

New missions

The CJF will adopt new missions to conduct deterrence to deter adversaries in the Euro-Atlantic area and, if required, beyond, to reassure allies and partners. For this purpose, a mechanism will be established to share, co-ordinate, and synchronise military activity and the deployment of UK and French forces worldwide. A dedicated cell will be established to operationalise the CJF, overseeing military strategic through to operational co-ordination and planning.