The below is a summary of and link to a commentary by Ambassador Peter Jenkins, Chair of British Pugwash.
The United Kingdom government recently announced, in the context of an integrated policy review, that it will move to an overall nuclear weapon stockpile of no more than 260 (from a previous target of no more than 180) and that it will extend its longstanding policy of deliberate ambiguity by no longer making public figures for its operational stockpile, deployed warheads and deployed missiles.
These decisions are best seen as symptomatic of a belief that the United Kingdom’s and NATO’s security environment has been deteriorating and that now Russia in particular poses a grave threat to the Kingdom and its NATO allies. Pugwash has an opportunity to react constructively to the decisions by exploring the reasons for the heightening of NATO/Russian tensions in recent years.
Additionally, use of nuclear weapons against non-nuclear aggressors in certain circumstances is envisaged (extension to the policy of deliberate ambiguity may be connected to this) and the right to review the UK’s negative security assurance to Non-Nuclear Weapon States is reserved. But nuclear weapon use in response to cyber-attacks and against non-state actors is ruled out, and the UK’s nuclear weapon submarines will remain at several days’ notice to fire.
The full statement can be read online here