UK nuclear deterrence

Information about the UK’s continuous at sea deterrent (CASD) and the Dreadnought programme to replace the Royal Navy’s Trident missile Vanguard Class Submarines.

The protection and defence of the UK is a primary responsibility of the government. The government is committed to maintaining the UK’s national nuclear deterrent based on a ballistic missile submarine for as long as the global security situation makes that necessary.

The continuous at sea deterrent (CASD) has provided the United Kingdom’s ultimate guarantee of security every day since 1969.

Since the mid ’90s, the 4 boats of the Vanguard Class have maintained CASD, ensuring 1 submarine was deployed at all times. The Dreadnought submarines are set to replace the Vanguard Class in the 2030s.

Read why the UK needs to maintain an independent nuclear deterrent here .

Michael Fallon, former Secretary of State for Defence explains why the UK needs a nuclear deterrent in the video below.

UK nuclear deterrence video


Read the full National Security Strategy and Strategic Defence and Security Review 2015 here.



UK Nuclear Deterrence Policy Hub

A full list of policy and related documents is available here.

Dreadnought submarine programme

Published 26 February 2016
Last updated 14 February 2018 + show all updates
  1. Updated nuclear deterrent information as of 14 February 2018.
  2. Added The United Kingdom’s future nuclear deterrent: 2017 update to Parliament.
  3. Added The United Kingdom’s future nuclear deterrent: 2016 update to Parliament
  4. Added speech for The case for the retention of the UK's independent nuclear deterrent.
  5. Added news article.
  6. First published.