The Nuclear Education Trust has also released a report on this topic you can access here: Stepping Back from the Brink

The world today stands closer to nuclear catastrophe than at any point since the end of the Cold War. Conflicts involving nuclear-armed states (the United States, Russia, the United Kingdom, France, China, India, Pakistan, North Korea and Israel) in Europe, the Middle East and South Asia, alongside rising tensions in East Asia, could all too easily escalate to a nuclear confrontation. Meanwhile, key arms control treaties have collapsed, and most nuclear powers, including the UK, are modernising their nuclear arsenals. Against this perilous backdrop, what could the UK do to help lead the world back from the brink?

The myths of tactical nuclear weapons and limited nuclear war

So-called “tactical” nuclear weapons (TNWs) are ones deployed to arenas of conflict or tension, such as those Russia has deployed to Belarus, and those the US has sited across five European NATO member states, with the UK, as of July 2025, reportedly now the sixth. Whilst these weapons can have relatively low explosive yields, the impact of their use would be anything but small. For example, the US B61-12 bombs can deliver explosive yields of up to 50 kilotons. This is several times more powerful than the atomic bombs dropped on Hiroshima and Nagasaki.

Any use of nuclear weapons, at whatever scale or size, would likely have very severe military as well as humanitarian and environmental consequences. Even a single detonation involving a relatively low-yield nuclear bomb could trigger uncontrollable escalation. National leaders faced with the ensuing chaos and fear of a completely new type of crisis would have no reliable way to contain events.

The fraying of the nuclear taboo

For decades, restraint regarding the use of nuclear weapons was maintained by the “nuclear taboo” — a shared global understanding that nuclear weapons are not legitimate tools of warfare. That taboo is eroding. For example, President Vladimir Putin’s threats to use nuclear weapons during the Russia-Ukraine war reintroduced nuclear brinkmanship into mainstream political discourse.

Russia’s actions are widely condemned, but only China has made a commitment never to use nuclear weapons first. The nuclear doctrines of the US, UK, France, Russia, Israel, North Korea, India and Pakistan all allow for first use under certain conditions. This collective ambiguity increases the risk of miscalculation and normalises threatening nuclear rhetoric.

A dangerous drift: Eroding treaties, escalating tensions

The collapse of key nuclear arms control agreements between the US and Russia — notably the Intermediate-Range Nuclear Forces (INF) Treaty in 2019 — has removed a vital guardrail that had at least banned ground-based “tactical” missiles with ranges between 500 and 5,500 km, such as the Cruise and SS20 Missiles. However, it is important to note that “battlefield” nuclear weapons – with a shorter range and often deployed from sea or air – were never banned

Recently, Moscow and Washington have developed new tactical nuclear weapons. Russia has tested its Burevestnik cruise missile, while the United States has fielded the W76-2 warhead on ballistic missile submarines. President Donald Trump also recently commented that the US will resume nuclear testing. China’s nuclear rearmament programme remains opaque, fuelling uncertainty and mistrust.

Learning from history

History offers important lessons on how these dangerous trends can be reversed. The Cuban Missile Crisis, the moment where the world came closest to nuclear war, demonstrated that diplomacy and mutual understanding — not military brinkmanship — are the only reliable paths to peace.

During the Cold War, the deployment of thousands of nuclear weapons in Europe brought humanity perilously close to disaster and also ignited a powerful civil society movement that demanded a different course: nuclear disarmament. The subsequent agreement of the INF Treaty in 1987, which eliminated a whole class of nuclear weapons and set the stage for several multilateral arms control and confidence and security-building measures, was a landmark achievement.

Rebuilding cooperation on nuclear arms control and disarmament

Now is the time for Russia to agree to a ceasefire and take part in good-faith negotiations to end the war in Ukraine, alongside all key participants in the conflict. In addition, Russia and the US should refrain from deploying TNWs and instead negotiate a legally binding treaty to eliminate them, complete with robust verification measures.

The nuclear powers — particularly the US, Russia and China — should also:

Reaffirm the nuclear taboo through joint declarations rejecting nuclear warfighting;
Commit to follow international law regarding the threat or use of force;
Renew and strengthen arms control and disarmament agreements, such as the New START Treaty, or at least maintain its limits after expiration;
Address the root causes of conflict, such as territorial disputes and economic inequality, including through sustained diplomacy.

These are challenging steps, but there is no other path to rebuilding stability. Even in the Cold War’s darkest moments, dialogue, arms-control mechanisms and crisis communication channels helped avert catastrophe. This way forward must not be lost in the fog of war preparations.

The UK’s critical role: From nuclear proliferator to peace broker

As Chair of the group of five ‘official’ nuclear weapon states in the run-up to the 2026 Nuclear Non-Proliferation Treaty Review Conference, the UK occupies a unique position, both as a nuclear possessor and a potential bridge between the superpowers and non-nuclear weapon states. Yet current British policy jeopardises that potentially positive role. There are four practical measures the UK should take to support strategic stability and demonstrate global leadership:

Reject nuclear sharing and prioritise transparency

The UK should not join NATO’s nuclear sharing arrangement, and thus not acquire F-35A aircraft or host US B61-12 bombs. Parliamentary and civil society scrutiny of nuclear deployments and procurement must increase through Select Committee inquiries and more mainstream media interest.

Reinvigorate global diplomacy

The UK should support high-level diplomacy among the nuclear powers to revive dialogue on arms control, disarmament and conflict prevention. As chair of the P5 process, the UK should urge that crisis stability between the major powers and the avoidance of arms races are prioritised.

Adopt a no-first-use policy

A commitment never to use nuclear weapons first would reduce escalation risks. Coupled with assurances not to threaten or use nuclear weapons against non-nuclear-weapon states, this stance would align the UK with NPT agreements to reduce the salience of nuclear weapons and encourage reciprocal restraint from others.

Engage with the Treaty on the Prohibition of Nuclear Weapons (TPNW)

It is time that the eyes of the world are reopened to the devastating effects of nuclear weapons. The UK should support the United Nations panel examining “the physical effects and societal consequences of a nuclear war on a local, regional and planetary scale”; and attend TPNW meetings as an observer, demonstrating concern and an openness to dialogue.

2026: A pivotal year

The year 2026 will be critical. It marks both the scheduled expiry of New START — the last remaining cap on US and Russian strategic arsenals — and the next NPT Review Conference. The message is unambiguous: continuing along the path of rearmament and confrontation invites catastrophe. The UK, as one of NATO’s more influential members, has a rare opportunity to steer policy toward restraint and away from the futile pursuit of “nuclear advantage.” To seize it, Britain must make bold choices — reject nuclear sharing, embrace transparency, champion diplomacy, and reaffirm the principle that nuclear weapons must never be used.

The European Leadership Network itself as an institution holds no formal policy positions. The opinions articulated above represent the views of the authors rather than the European Leadership Network or its members. The ELN aims to encourage debates that will help develop Europe’s capacity to address the pressing foreign, defence, and security policy challenges of our time, to further its charitable purposes.

Image credit: Wikimedia Commons / Lauren Hurley / No 10 Downing Street