Competing perceptions of nuclear deterrence are no longer peripheral disagreements within the Nuclear Non-Proliferation Treaty (NPT) – they are driving deep structural divisions that risk paralysing the regime. The failure by states at this year’s NPT Preparatory Committee to agree on measures to strengthen the treaty ahead of the 2026 Review Conference was a sobering sign of the divisions fracturing the regime.

Of course, opposing views on nuclear deterrence are not the sole cause of gridlock within the NPT. However, they indicate deeper conflicts about which security strategies states can and should rely upon. For nuclear-weapons states and allies, nuclear deterrence remains a necessary pillar of international security and regional stability. Non-nuclear-weapons states see deterrence as outdated and dangerous, arguing it ultimately increases the risk of nuclear conflict. Reflecting these frictions, debates within the NPT increasingly focus on the legitimacy of extended nuclear deterrence and nuclear sharing arrangements – practices whose compatibility with the treaty’s objectives remains deeply contested.

If unaddressed, these fractures risk deepening polarisation within the regime and could significantly undermine efforts to build consensus at the 2026 Review Conference.

To preserve the NPT, states should bridge the deterrence divide by acknowledging divergent security perspectives and addressing legitimate concerns on all sides. All nuclear-weapons states, as well as NATO allies, should articulate the security rationale of nuclear deterrence more clearly, while addressing the double standards their policies imply. Non-nuclear-weapons states should engage with the broader security implications of renouncing practices of nuclear deterrence, as well as the deterrence strategies of Russia and China. Strengthening measures such as codifying Negative Security Assurances (NSA) – guarantees by nuclear-weapons states not to use or threaten to use nuclear weapons against non-nuclear-weapons states – and enhancing regional security frameworks can help reduce reliance on nuclear weapons and revive disarmament commitments.

Geopolitical insecurities feed into polarisation

Today’s geopolitical landscape amplifies divergent views on nuclear deterrence, where conflicts and great-power rivalries fuel mistrust and hinder bridge-building within the NPT.

Russia’s war in Ukraine and the escalating NATO-Russia antagonism cast a long shadow over the non-proliferation regime, fuelling nuclear modernisation and expanding the role of nuclear weapons in military doctrines. Russia’s nuclear threats and posturing have heightened anxieties in Europe over possible escalation into nuclear war. In light of fears about Russia’s long-term intentions – and concerns over declining US support – discussions about a potential European deterrent or expanded NATO nuclear sharing are seen as logical by many NATO states. Doubts over the US commitment to extended deterrence also fuel debates in South Korea and Japan amid North Korea’s expanding nuclear capabilities and China’s nuclear build-up.

These debates heighten concerns among many non-nuclear-weapons states, who fear that such developments increase the salience of nuclear weapons and undermine disarmament efforts.

Together, these shifts in attitude and policies contribute to entrenching opposing positions on nuclear deterrence – especially regarding extended deterrence and nuclear sharing. These divisions extend beyond policy disputes, reflecting deeper fault lines in how states understand security within the context of the NPT.

Competing narratives on nuclear deterrence

Long-standing divisions over nuclear deterrence within the NPT regime most visibly revolve around fundamentally different interpretations of the role and legitimacy of extended deterrence and nuclear sharing. These divides reflect not only political differences, but also clashing security narratives and distrust in the nuclear-weapons states’ disarmament commitments.

The P3 states – the United States, United Kingdom, and France – alongside their NATO allies, consistently defend these arrangements as essential to alliance security and fully compatible with the NPT. Their argument: these arrangements have been accepted as a security framework before the NPT was negotiated and are an essential non-proliferation instrument in that they offer positive nuclear security assurances.

Many non-nuclear-weapons states, especially from the Global South, fundamentally oppose these narratives. They argue that nuclear deterrence practices violate the spirit, if not the letter, of the disarmament commitments in the NPT; that nuclear deterrence perpetuates nuclear weapons possession, derails disarmament efforts, and inherently raises the risk of nuclear conflict. Within the context of the Treaty on the Prohibition of Nuclear Weapons (TPNW), states have sought to reframe debates about the security benefits of nuclear deterrence practices. They advocate for an alternative security framework that would highlight the humanitarian consequences and inherent risks of nuclear deterrence.

China has been adept at exploiting such divisions. Increasingly assertive, China portrays extended deterrence as a threat to global stability and the NPT – citing concerns about strategic stability. China uses this narrative strategically to position itself as a “responsible” nuclear-weapons state that takes the security concerns of non-nuclear-weapons states seriously. Russia, too, continues to exploit divisions over nuclear sharing, branding NATO practices as destabilising and hypocritical – a narrative it still promotes, despite, or to deflect from, its own recent deployment of nuclear weapons in Belarus. While clearly hypocritical, Russia’s narrative resonates with many non-aligned states frustrated by what they perceive as Western double standards: advocating extended deterrence for themselves while demanding that other states refrain from nuclear weapons.

Can the NPT survive the deterrence divide?

The consequences of these fractures affect the regime’s core functioning and legitimacy. Rather than fostering genuine dialogue, exchanges within the NPT become increasingly performative, hardening positions and reinforcing existing blocs. The polarised debate over nuclear deterrence leaves little room for bridge-building or serious engagement on diverging security perceptions or alternative security structures.

If these divergent perceptions on nuclear deterrence remain unaddressed, they could prevent consensus-building and weaken the prospects for any agreement at the 2026 Review Conference. The entrenchment of incompatible narratives – nuclear deterrence is either perceived as purely defensive and distinguishable from explicit nuclear threats, or as a menace to security that is always underpinned by implicit threats – risks alienating states and fuelling disillusionment with the treaty.

The increasing salience of nuclear deterrence, embodied by nuclear sharing arrangements, has reinforced scepticism among non-nuclear-weapons states over the state of disarmament and heightened concerns about nuclear risks. The fracture provides strategic leverage to China and Russia, who increasingly capitalise on concerns over NATO’s nuclear sharing practices. Without genuine attempts to bridge the divide by acknowledging and seriously engaging with different security perceptions, the NPT could enter the next review cycle even more polarised than before.

More than stagnation is at stake. Avoiding discussions on nuclear deterrence risks reinforcing perceptions of hypocrisy, driving disengagement from non-nuclear-weapons states, and eroding the NPT’s credibility as the cornerstone of the multilateral nuclear order.

The road to 2026

Diverging perceptions of nuclear deterrence are not merely rhetorical – they pose a core challenge to the NPT’s future. Addressing these conflicting narratives will be essential to success in 2026. This requires meaningful dialogue within the NPT framework on differing security perceptions.

All nuclear-weapons states should take greater responsibility for reducing nuclear risks and addressing the deterrence divide. This includes increasing transparency around their doctrines, engaging more honestly with the double standards inherent in their deterrence postures, and refraining from actions that further elevate the salience of nuclear weapons. Such steps are essential to rebuilding trust across the NPT membership and reaffirming a shared commitment to the treaty’s long-term legitimacy.

States reliant on extended nuclear deterrence, particularly NATO members, should reconsider how they articulate the security rationale behind their posture, including why Russian nuclear sharing should be considered more problematic than their own practices. At the same time, they should counter misleading narratives advanced by China and Russia, exposing contradictions and holding both accountable for their practices.

Non-nuclear-weapons states, in turn, should move beyond general objections to NATO nuclear sharing and explicitly address the implications of Russian or Chinese deterrence practices. Simply singling out NATO nuclear deterrence practices risks reinforcing the impression among NATO states that they are unfairly targeted while Russia and China avoid scrutiny.

The NPT should be revitalised as a forum for addressing these difficult but unavoidable questions. That includes engaging with the security value many states attribute to nuclear deterrence and addressing security perspectives articulated through the TPNW process that have long been ignored within the multilateral discourse. Even if some states reject the premise that nuclear deterrence prevents proliferation in NATO, Japan or South Korea, they should consider what alternative security assurances could serve that role. Likewise, NATO states should reflect on the growing salience of nuclear deterrence, including debates around independent deterrents or alternative sharing arrangements in Europe. Such debates signal that nuclear weapons are considered valuable and could therefore undermine non-proliferation efforts.

Concrete steps to strengthen alternative security provisions would not only signal that there is still room for progress under Article VI but could also, in the long term, help reduce the perceived need for extended nuclear deterrence. This includes making Negative Security Assurances more robust – since their credibility has faced a serious blow with Russia’s threats against Ukraine. Stepping up support for Nuclear-Weapon-Free Zones and a treaty on NSAs would further reinforce these efforts.

Preserving the NPT’s credibility requires states to revisit long-held assumptions about nuclear deterrence and reimagine the security architecture underpinning the Treaty. Avoiding debates on nuclear sharing and extended deterrence won’t save the regime – it will deepen fractures.

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 / Buroll