Macron and Starmer to sign historic nuclear deterrence pact

Thursday 10 July 2025 - 15:20

By: Dakir Madiha

Macron and Starmer to sign historic nuclear deterrence pact

France and the United Kingdom have announced plans to coordinate their nuclear deterrence strategies, pledging to protect Europe from any “extreme threat.” This historic agreement marks a major evolution in their defense doctrine amidst growing security concerns in Europe.

A united nuclear strategy

On Thursday, French President Emmanuel Macron and British Prime Minister Keir Starmer will sign a declaration affirming that their nuclear deterrence systems, while independent, can be coordinated. According to statements from the UK Ministry of Defence and the French presidency, any extreme threat to Europe will prompt a joint response from both nations, though the nature of such a response remains unspecified.

This agreement follows months of discussions initiated by Macron to explore nuclear deterrence cooperation with European neighbors. As part of the deal, a newly established "nuclear oversight group," co-chaired by the Élysée and the UK Cabinet Office, will oversee coordination of policies, capabilities, and operations.

A step beyond past agreements

The announcement is the first significant update to Franco-British nuclear cooperation since the 1995 Chequers Declaration, which stated that the two nations’ vital interests were intertwined. However, today’s agreement goes further, introducing unprecedented military and political coordination.

“This represents an unprecedented level of coordination in nuclear deterrence,” said Heloïse Fayet, a nuclear policy expert at the French Institute of International Relations (Ifri).

The agreement also builds on the 2010 Lancaster House Treaties, which formalized joint military initiatives, including the creation of a Combined Joint Expeditionary Force (CJEF). This force now serves as the foundation for a Franco-British coalition of 30 nations supporting Ukraine’s defense and a future ceasefire with Russia.

Shifting defense priorities in Europe

The renewed partnership comes against the backdrop of the Russian invasion of Ukraine and uncertainty about U.S. commitments to European security, particularly during Donald Trump’s presidency. These factors have prompted France and the UK—Western Europe’s only nuclear powers—to strengthen their defense collaboration.

The bilateral summit will also include announcements on accelerating the joint Scalp/Storm Shadow missile program and launching a new phase of cruise missile and anti-ship missile development.

Strengthening Europe’s defense coalition

On Thursday, Macron and Starmer will also co-chair a video conference of the Franco-British coalition, which includes representatives from the United States. This group aims to bolster Ukraine’s defense capabilities and work toward a future peace agreement with Russia.

As part of his state visit, Macron will also attend a banquet at Windsor Castle hosted by King Charles III, further strengthening Franco-British ties.