Is London shifting from nuclear deterrence to war-fighting?

The deployment of high-precision, variable-yield counter-force weapons signals a willingness to carry out retaliatory or pre-emptive nuclear strikes on an adversary.

Bulletin, By S.M. Amadae, Tom Stevenson | Analysis | July 10, 2026

For most of the past three decades, one might almost have said the United Kingdom had a glowing record on nuclear non-proliferation: Britain was the only major nuclear power to operate a minimum deterrent based on a single delivery system; it supported international non-proliferation initiatives; and the UK government had spent 30 years reducing its nuclear stockpile. No more. Instead, London now builds momentum supporting a new wave of nuclear proliferation under the auspices of NATO’s nuclear sharing.

In the last five years, Britain has quietly moved to increase the maximum size of its nuclear stockpile and revise its nuclear doctrine, and it is now acquiring an additional nuclear capability. In concert with the United States, the UK government is expanding the deployment of non-strategic (tactical) nuclear weapons in a way that could destabilize the strategic balance in Europe.

In doing so, London is reversing decades of gradual progress on disarmament without serious analysis of the strategic implications or public consultation, and at a time when there is less support for nuclear diplomacy than at any point in recent history.

New systems and more weapons. In June 2025, the United Kingdom announced plans to acquire Lockheed Martin F-35As that are the first stealth fighter jets certified to carry variable-yield thermonuclear B61-12 gravity bombs. The 12 F-35As would be ordered in place of F-35B fighter jets, which are designed for use on aircraft carriers but are not nuclear-capable. At the Hague summit last year, the United Kingdom then announced it would be joining NATO’s air-launched nuclear mission and putting those planes to work carrying US nuclear bombs. Though it has still not been officially confirmed, US B61-12s were almost certainly moved to RAF Lakenheath in July 2025.^[1] Media briefings at the time suggested the UK government was also in talks with Washington on acquiring non-strategic B61-12 bombs of its own, but no such agreement has publicly emerged yet.

On the surface, the United Kingdom’s decision to acquire tactical nuclear capability appeared to be part of a natural evolution in European strategic planning prompted by Russia’s invasion of Ukraine in 2022. But London’s acquisition of F-35As and the deployment of US B61-12s are just the latest examples of a longer trend in the United Kingdom’s nuclear posture. In 2022, RAF Lakenheath had already undergone infrastructure modernization necessary for the return of US nuclear weapons.

Before that, in 2021, the UK government decided to raise the maximum cap on the number of warheads in its arsenal by more than 40 percent. In 2010, the UK government stated that it would continue to reduce its warhead stockpile—at the time numbering 225 warheads—and cap its future arsenal at a maximum of 180 warheads. But in 2021, it suddenly raised the cap to 260 warheads. Despite being a reversal of decades of gradual reductions in the United Kingdom’s projected nuclear stockpile, that decision was slipped onto page 76 of the government’s Integrated Review of Security, Defence, Development, and Foreign Policy.

Policy implications. The United Kingdom has also made a quiet change to its nuclear doctrine, introducing a “right to review” the use of nuclear weapons against non-nuclear states under certain circumstances. Together with the decision to raise the warhead cap, this constituted a dramatic strategic change for which there was no discernible democratic mandate and no public discussion.

At the time, even the best-informed commentators on UK nuclear affairs were unaware of the motivation. One argument, put forward by nuclear historian Lawrence Freedman, was that a larger stockpile of 260 warheads might allow the United Kingdom to have two fully armed nuclear submarines (each potentially carrying a maximum of 128 warheads on 16 missiles) on patrol at once. That the increase in stockpile size was motivated by plans for the United Kingdom to have the option of acquiring a non-strategic nuclear capability only emerged later.

The decision to station B61-12s on UK soil amounts to a de facto settlement of the long‑running debate over adopting a doctrine of no‑first‑use or sole‑purpose, and over the future of tactical nuclear weapons in NATO. The deployment of high-precision, variable-yield counter-force weapons signals a willingness to carry out retaliatory or pre-emptive nuclear strikes on an adversary.

Due to their enhanced guidance systems, B61-12 bombs, coupled with the dual-capable stealth F-35A, also have the potential to alter the geopolitical balance in Europe. The UK B61-12 adoption paves the way for further proliferation of these weapons throughout Europe, cements the normalization of nuclear weapons, and challenges the guaranteed second-strike survivability of adversaries’ nuclear command and control and strategic weapons systems.

Since the end of the Cold War, the United States and, by extension, NATO have become, in the words of the now Under Secretary of Defense for Policy Elbridge Colby, “accustomed to escalation dominance,” the strategic objective of achieving battlefield superiority on all rungs of escalation. This aim relies on maintaining asymmetrical advantage, which is not a sound doctrine against a nuclear peer competitor: It is destabilizing and stokes further arms races.

The combination of F-35A fighter jets and B61-12 bombs gives NATO a stealth-enabled, precision counterforce tool designed to deter by denial by holding Russian nuclear and nuclear command and control assets at credible risk. In theory, they provide limited escalation-control options, such as pre-emptive or tit-for-tat strikes at tailored yield. These technological developments make Russian nuclear forces and command systems both more vulnerable in crisis and less certain for guaranteeing second-strike capability.

From arms control hero to nuclear war fighter. Until recently, UK efforts on exemplary disarmament were comparatively good. The United Kingdom was the only major nuclear state that had limited itself to a single deterrence system (the Trident submarine-launched ballistic missile). The UK government had made incremental reductions in its nuclear stockpile since 1980. With US B61s having returned to the United Kingdom, that record has now been overturned…………………………………………………………………………………………………………………………………………………………………………….

No rationale, real danger. The strategic need for the United Kingdom to operate air-launched tactical nuclear weapons has not been clearly presented either by US officials or the UK government. In addition, these weapons arguably increase the United Kingdom’s reliance on US weapons platforms at a time of transatlantic political divergence…………………………………………………………………………………………………….

The UK government and the United States should carefully revisit the assumptions that led to this point. There is no justifiable reason for the United Kingdom and NATO to expand non-strategic capabilities while also maintaining a no-first-use doctrine unless they are planning a pre-emptive nuclear strike deep into Russian territory, or the territory of another nuclear weapons state, or against a non-nuclear weapons state. NATO member states, like Finland and Poland, are promoting their participation in nuclear sharing and planning. Both understandably perceive an existential threat from Russia, and they are now also considering hosting US nuclear weapons and joining France’s forward deterrence initiative. But with the United Kingdom having already made that choice, it has the dubious distinction of leading the way in normalizing more first-use tactical nuclear capabilities in Europe without comprehensive analysis of the strategic implications. This nuclear brinkmanship, directly pertinent to the Ukraine war, offers the false promise of security for some at the cost of dooming security for all. https://thebulletin.org/2026/07/is-london-shifting-from-nuclear-deterrence-to-war-fighting/?utm_source=ActiveCampaign&utm_medium=email&utm_content=Is%20London%20shifting%20from%20nuclear%20deterrence%20to%20war-fighting%3F&utm_campaign=20260709%20Thursday%20Newsletter%20%28Copy%29