British defence policy
This fact sheet looks at the history and foundations of British defence policy, reviewing the development of the «special relationship» with the United States and the United Kingdom's anchorage in NATO. It then shows how the Strategic Defence Review published in 2025 represents a turning point, establishing a «NATO-First» posture, refocusing on Euro-Atlantic security and explicitly preparing for a high-intensity conflict. Finally, it highlights the strategic role that the UK could play in the defence of Europe, particularly at the interface between NATO and the EU, as the transatlantic link recomposes itself.
Franco-British defence cooperation
This fact sheet focuses on Franco-British military cooperation, from its historical foundations marked by the Entente Cordiale of 1904, the First World War, the Battle of Dunkirk (1940) and the Suez Crisis (1956) to post-Cold War operational rapprochement. It analyses the role of the Treaties of Lancaster House (2010) and Lancaster 2.0 (2025), which institutionalise the Franco-British Joint Expeditionary Force (CJEF) and strengthen nuclear and capability coordination, while highlighting the limits of this solidarity in the face of national trade-offs and divergent industrial choices. Finally, it sheds light on the prospects for the relationship, between opportunities for European rapprochement post-Brexit and the challenges posed by competition in the development of military capabilities. It also sheds light on the differing approaches of Paris and London to Ukraine, in a context of strategic recomposition of European defence.
