This week the UK government has announced its intention to undertake a new nuclear mission. Keir Starmer indicated that the purchase of 12 US F-35A aircraft will provide the capacity for the UK to threaten states with US-made B61 tactical nuclear bombs. The Ministry of Defence implies that UK pilots would be trained to enable these aircraft to provide a second leg to the UK nuclear weapons programme, threatening adversaries with smaller more usable and ‘credible’ nuclear weapons in addition to the UK’s current large-scale strategic nuclear weapons system.
The introduction of a new range of tactical nuclear weapons would be a mammoth shift in UK nuclear strategy, unparalleled in the past 25 years. Contrary to claims by some, the recent Strategic Defence Review (SDR) does not offer justification for this dramatic development.[1] The review only recommended “commencing discussions with the United States and NATO on the potential benefits and feasibility of enhanced UK participation in NATO’s nuclear mission”. The review has not considered the pitfalls of various options or even outlined what ‘enhanced UK participation’ might look like.
Lord Robertson, the chair of the independent review team, was asked by the Defence Committee about the possibility of the UK hosting US air-launched nuclear weapons or developing its own. In reply, he stated, “We considered it. The fact that it’s not there indicates that we weren’t terribly enthusiastic about it. When I was Defence Secretary the last time round, I got rid of the free-fall bombs.”
Let’s be clear: there is no identifiable public support for the UK’s involvement in tactical, more ‘useable’ nuclear weapons; no Parliamentary scrutiny of this proposal to date; and no case set out by the Government outlining the pros and cons of such a major shift in UK defence policy.
Why are tactical nuclear weapons being considered? To do this question justice we need to delve into the controversial policy of nuclear deterrence, the theory of which is that the threat or potential of one party using force will convince another party to refrain from initiating some other course of action. The SDR acknowledges that Russia’s aggressive adventurism is driving the UK’s strategic thinking. Nuclear planners in Whitehall are concerned that the UK’s current nuclear weapons lack credibility as a deterrent across a range of scenarios. They worry that the UK is unable to influence the escalation ladder that climbs from conventional conflict to all-out global nuclear war, if the UK only possesses large warheads several times the size of the Hiroshima bomb. There is no evidence that President Putin, despite his brutal and ruthless tendencies, would consider using a nuclear weapon on European states. Yet the fact that he could is apparently enough for some nuclear planners to recommend spending billions of pounds on new warheads and delivery systems. This shift would reverse undertakings that that the UK has made at Nuclear Non-Proliferation Treaty (NPT) Review Conferences, thereby weakening the NPT, which is the only international agreement binding nuclear weapons-holding states to the goal of disarmament.
It’s helpful to consider what role tactical nuclear weapons might play in two potential scenarios involving Russian aggression. The first concerns suppression of conventional conflict. Imagine Russia was to invade a neighbouring state, say Lithuania or Estonia, for which they could mobilise troops in numbers that would overwhelm a NATO conventional response. Given Russia’s invasion of Ukraine, this future possibility cannot be entirely dismissed, and it is prudent to give it serious consideration. The hypothesis is that if the UK had tactical nuclear weapons this might dissuade President Putin or another future Russian leader from crossing the border with troops. Russia might assess that the United States lacked the resolve to use its tactical nuclear weapons based in Europe. In this case, Russia would then be deterred by the faint possibility of the UK breaking the global nuclear taboo and using nuclear weapons for the first time since the Second World War in a counterforce attack against Russian military assets. This possibility, vanishingly remote as it is, is thought to have more credibility if the UK were to possess tactical nuclear weapons as an alternative to its hugely destructive strategic nuclear weapons.
However, the supposed deterrent effect of the UK’s nuclear weapons in this scenario does not hold water. Russia’s counter-strategy would see it engaging in hybrid warfare, destabilising regions close to the Russian border through support of provocateurs, alleging ‘extremism’ on the part of local and national political figures to provide cover for a low-level military intervention with the option to expand later. There are plenty of options open to Russia to initiate a military intervention that at no point would involve a step significant enough to conceivably warrant resort to tactical nuclear weapons. This renders UK nuclear weapons a useless deterrent against a conventional attack by Russia.
The second scenario is one that is maybe more familiar in habitual nuclear deterrence thinking. It concerns deterrence of a Russian nuclear attack, and Ukraine is a pertinent case study. Over the past three years, Russia has increased its nuclear rhetoric. There are concerns that were Russia to lose this conventional conflict and be pushed out of the four regions of Donetsk, Kherson, Luhansk and Zaporizhzhia, it could make good on recent nuclear threats. It could, let’s say, bomb military bases in Ukraine or NATO states with its tactical nuclear weapons. Western nuclear strategists suggest that if the UK had tactical nuclear weapons of a similar nature, then Russia would be deterred from a first use of nuclear weapons. The main difficulty here is the assumed plausibility of Russian ‘first use’. While the rhetoric coming from Moscow is certainly alarming at times, Russia has nothing whatsoever to gain from first use in this or any similar scenario, and everything to lose with respect to its relationship with China and India and its standing and trading position in the international community. It is precisely this diplomatic and economic cost to Russia that the UK government could look to strengthen by reinforcing nuclear restraint.
It is only when we delve into the smoke and mirrors of nuclear deterrence thinking that we can assess the merit of a proposed allocation of vast sums of public money to develop and maintain a whole new category of nuclear weapons. Unfortunately, while nuclear scenario planning takes place in Whitehall, it is discouraged in political debate in the Parliament across the road. In response to any MP’s question on deterrence strategy, the responsible government minister is likely to decline to comment with respect to any particular adversary.[2] This imposes a serious constraint on the democratic process. Democratic debate is sacrificed in the name of the extremely vague and unsafe notion of protecting ‘deterrence credibility’.
The consultation on the SDR invited input from organisations, including churches and faith groups, but discouraged comment on the current policies around the UK’s strategic nuclear weapons.[3] The review panel will have missed the opportunity to hear a range of critical views on both the missteps of UK government policy by reducing transparency of its nuclear stockpile, and the affordability of an expanded UK nuclear role and opportunity costs. It also meant that it did not hear proposals about opportunities for the UK government to engage more constructively with non-nuclear weapons states, the UK role in shoring up the global non-proliferation architecture, and the role of UK faith groups and others in a global movement around the Treaty on the Prohibition of Nuclear Weapons.
The SDR expresses concern that public trust in nuclear deterrence is not what it might be. Consequently, one of the SDR’s 62 recommendations is for a “public communications campaign that conveys the fundamental importance and necessity of the deterrent”. A PR campaign should not be the priority. Rather, a more honest and open debate about the actual value of a nuclear deterrent would be much more befitting of a democracy.
This is my last blog as a staff member of the Joint Public Issues Team, so on a personal note I would like to say what a pleasure it has been to converse with members across our churches. I know that the team will continue to provide good analysis and support to our churches and church members on contemporary issues, enabling us all to speak out and influence politics and current debates in society.
[1] UK Defence Journal – Britain considering fleet of nuclear strike aircraft. The Times – Britain considering fleet of nuclear strike aircraft
[2] Luke Pollard in response to Sir Desmond Swayne “I decline that polite invitation to detail our nuclear strategy. That ambiguity is absolutely certain …” 2 June 2025 https://hansard.parliament.uk/Commons/2025-06-02/debates/14BA9D9E-231D-46CC-97AD-87467397E3DA/UKNuclearDeterrent. John Healey in response to Ben Obese-Jecty 2 June 2025 “I will not comment in public on those discussions …” https://hansard.parliament.uk/commons/2025-06-02/debates/AA250D32-663A-462C-98F4-64DD8DF389A7/StrategicDefenceReview. MPs receive news of nuclear weapons on UK soil from the US Department of Defence while the UK Government continues to deny scrutiny. Luke Pollard in response to Shockat Adam: – “It remains longstanding UK and NATO policy to neither confirm nor deny the presence of nuclear weapons at any given location.” https://questions-statements.parliament.uk/written-questions/detail/2025-01-21/25424/
[3] This did not dissuade the Baptist Union, Methodist Church and United Reformed Church from offering comment on the Government’s ‘triple lock’ on Trident in our joint evidence submission to the SDR, despite the consultation guidance.