Mike, I’ve tried posting a comment but it did not appear with ‘awaiting moderation’ and so I tried posting again and I was told my double comments had been deleted. To counteract any glitches here is my comment, but if you see a repeat please delete one of them.

A comment issued by Dr Philip Webber, (14th Jan 16) from Scientists from Global Responsibility, summarises the flaws in the theory and practice of nuclear deterrence for the UK, re the 3 key arguments from the government’s Strategic Defence and Security Review (SDSR)1 (November 2015) 1) UK weapons are at a “minimum, credible” level; 2)
The nuclear deterrence effect works “every day”; 3) They have kept the UK out of conflicts for the last six decades, his rational response: http://www.sgr.org.uk/resources/trident-deterrence-and-uk-security

And a report, published 1st December 2015 by the Stockholm International Peace Research Institute (SIPRI) and the UK-based Nuclear Education Trust (NET), shows that UK strategic nuclear weapons have been a constant ‘contribution’ to NATO nuclear doctrine since the late 1950s but that ‘the exact nature of that contribution has become increasingly obscure since the end of the Cold War’.
http://www.nucleareducationtrust.org/british-bomb-and-nato

Also worth mentioning, in the rabid rational of nuclear deterrents here’s a snippet from the British Ministry of Defence’s 1998 Strategic Defence Review which has a ‘sub-strategic role’ for Trident. They stated “‘the credibility of deterrence also depends on retaining an option for a limited strike that would not automatically lead to a full scale nuclear exchange’ as a means of demonstrating resolve or conveying a political message’”

Why I am not reassured that this would not automatically lead to a full scale nuclear war… after all Trident’s ‘mingled asset ownership’ has drawn its missile stock, randomly, from a pile in Georgia, USA, before being fitted with the lethal stuff in Aldermaston. Please ref page 381 of the 2008 SIPRI Handbook, this link takes you directly to that page:
https://books.google.co.uk/books?id=EAyQ9KCJE2gC&pg=PA381&lpg=PA381&dq=Stockholm+International+Peace+Research+Institute%E2%80%99s+trident&source=bl&ots=omVmzbTFDw&sig=Qfo_8O8PBm4f6nKHLPwfGGEBQg8&hl=en&sa=X&ved=0ahUKEwj-h72Y8a3KAhWBtBQKHQ-CAjYQ6AEIRzAI#v=onepage&q=Stockholm%20International%20Peace%20Research%20Institute%E2%80%99s%20trident&f=false

Trident is not fit for purpose, is not OURS and therefore not an independent retaliatory deterrent, it’s costs are exorbitant and foolhardy when very few people with a brain would actually promote the use of such weapons and even fewer who have the final say. It is a self defeating exercise since going nuclear keeps no-one safe.