This month marks 50 years of our nuclear weapons submarines sailing out of Faslane, Scotland. Powered by silent nuclear reactors, the submarines are designed to be undetectable. The Ministry of Defence wants a national celebration of the undoubted technical achievements of our Continuous At Sea Deterrence (CASD) and the dedication of personnel who serve on submarines. The official spin on the UK’s nuclear weapons is that they have kept the peace for 50 years. If you repeat a line often enough and for long enough, you can convince yourself and others of quite a lot.
The UK government believes that not only have these submarines prevented the UK from coming under nuclear attack, but that they have prevented conventional conflict between NATO states and other adversaries. This is the dominant thinking within the Ministry of Defence and Foreign Office. Consequently it is also likely to be the default position for MPs (the notable exception being MPs and MSPs in the Scottish National Party).
Yet, when in office as Secretary of State for Defence, Lord (Des) Browne tried to unearth all of the evidence for the efficacy of deterrence in his Department’s records. The data was rather thin on the ground and ultimately inconclusive. He confessed that two different people coming into his position could look at that data and quite easily come up with opposing opinions on the alleged deterrence effect. Even so, we are still told that the weapons are essential for our security and dissenting voices risk being thrown into a political wilderness.
For quite valid reasons, military officers rarely publicly challenge official policy. But in retirement they are freer to speak their mind. “Our independent deterrent has become virtually irrelevant” and “completely useless” said Field Marshal Lord Bramall, former head of the armed forces, writing in The Times. General Sir Hugh Beach provides a detailed historical analysis of deterrence and concludes that “history does not provide a single instance where a non-nuclear state has been compelled to do something it did not want to do, or deterred from doing something that it did want to, by a nuclear-weapon state in virtue of the latter’s nuclear weapons.” 
Yet maintaining the belief system of nuclear deterrence is essential in order to maximise the notional deterrence value of the UK’s nuclear arsenal. Our Government wants to convince potential adversaries that there are circumstances in which the UK might actually use its nuclear weapons, even though their use would be contrary to our understanding of the principles in international humanitarian law and offensive to our sense of public decency and morality. In order to be truly convincing our government finds itself engaging in a project of self-delusion. Former Defence Secretary, Sir Michael Fallon, stated categorically that there would be circumstances in which Theresa May would fire off nuclear missiles as a first strike. I wonder whether, following her departure from office and after a further respectable passage of time, the Prime Minister might clarify her thinking and admit that she could not see herself agreeing to a nuclear first strike on another nation.
Unfortunately we are somewhat constrained when it comes to calling our Ministers to account on such statements. Even with the UK Freedom of Information Act (2000) we still come up against the wall of ‘national security interest’ that privileges the withholding of information. A policy of deliberate ambiguity around the use of nuclear weapons is inherent to the UK’s strategic posture. To maintain this ambiguity we must compromise our democratic principles of transparency and accountability with the concomitant risk of self-delusion.
However, whether as citizens or churches, we need not let ourselves be taken in. The churches in the UK are increasingly clear in asserting their unequivocal and principled opposition to nuclear weapons. They can speak out while also upholding and supporting young men and women in the Royal Navy who go out on patrol for months at a time. We are thankful for those who serve in the forces. Ultimately they serve in various roles on the basis of a defence posture that is not their personal responsibility but rather is the concern of Parliament and of all of us.
Today national governments and civil society groups across the world are supporting the new Treaty on the Prohibition of Nuclear Weapons. Such groups are advocating for the establishment of norms under international law and among these groups our churches find natural allies. Our church institutions must help to bring about a more open and honest national debate. Threats to our security today are more diverse than during the years of Cold War. The UK’s reliance on the threat of use of weapons of mass destruction is a feature of our past. After 50 years it can no longer be a feature of our future.
 Comments made by Lord (Des) Browne when launching the BASIC Trident Commission in Parliament in February 2011.
 Others take the view that with the diverse threats that we now face, the enormous effort and expense afforded to nuclear weapons is disproportionate and is compromising other military capabilities.
 For example, in July 2018, the General Synod of the Church of England passed resolution to “welcome the 2017 UN Treaty on the Prohibition of Nuclear Weapons and the clear signal it sends by a majority of UN Member States that nuclear weapons are both dangerous and unnecessary”. The Synod rejected an amendment that would have called on the UK Government to sign the treaty now.