In data: Could Britain and France’s nuclear weapons protect Europe?

Britain’s nuclear capability depends on the US and France reserves its for national defence. How might they cooperate to bolster NATO’s ultimate ability to defend itself?

The World Today

Published 9 June 2025

Updated 14 July 2025

Image — HMS Vigilant is one of four submarines able to carry the UK’s Trident nuclear deterrent, stationed in Faslane, Scotland. Photo: James Glossop/ WPA Pool via Getty Images.

Britain’s recent Strategic Defence Review recommends seeking a ‘closer relationship’ with France, ‘its European nuclear ally’. But Britain depends on US support for its nuclear capability and France, which is not part of the NATO Nuclear Planning Group, reserves its for national defence. In recent months, questions have been raised about the United States’ commitment to allies – how might Britain and France extend their ‘nuclear umbrella’? 

Entente nuclear?

Britain and France have about 515 nuclear warheads between them – a fraction of Russia’s nuclear inventory, which is thought to number more than 5,000. 

Access the archive

The current issue is open access with previous editions reserved for our members and magazine subscribers.

Subscribe