How Resilient is the Non-proliferation Norm? — Lessons From Research on Norm Survival
Lisa Hultman, Professor of Peace and Conflict Research & Director of AMC
Eva Norris, Master's student in International Law, Geneva Graduate Institute & intern with AMC
From 27 April until 22 May 2026, diplomats and national delegations will gather at the United Nations Headquarters in New York for the five-yearly Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). This conference takes place during a period of heightened geopolitical instability. Europe currently finds itself in an increasingly precarious security situation following threats from both the US and Russia.
Nuclear deterrence is back on the political agenda and several states are beginning to renegotiate their commitment to disarmament and non-deployment of nuclear weapons. Discussions about nuclear expansion and increasing European independence in terms of military and defence capabilities, including a stronger European shared nuclear umbrella, have become ever more present. German Chancellor Merz has discussed a German-French nuclear umbrella, while Sweden’s Prime Minister Kristersson held talks with France and the United Kingdom. Most recently, Finland revealed plans to abandon their ban on hosting nuclear weapons on Finnish territory. Polish Prime Minister Tusk even indicated that Poland might consider pursuing its own nuclear weapons, which would be a direct violation of the NPT.
These developments, while not all incompatible with the NPT, raise concerns about the resilience of the non-proliferation norm. Research has shown that security guarantees substantially lower the likelihood that recipients will pursue proliferation. But this is exactly where the problem lies now: security guarantees are eroding and existential security threats are growing.
We reflect on this issue by turning to the broader phenomena of commitment to humanitarian agreements and international norms. We make three observations. First, states are often willing to trade collective security and civilian protection for national security in times of perceived threat. Second, withdrawals from humanitarian multilateral agreements are rare, yet recent examples provide a worrisome signal. Third, international norms can be protected, especially if part of a larger norm cluster.
Collective vs. national security
The NPT is often described as the cornerstone of the nuclear order. One of its strengths lies in its global coverage: the treaty has 191 state parties. Even though the nuclear weapon states have at times been criticised for weak commitment, the NPT has created stability and predictability. When European states now begin to renegotiate their policies on nuclear weapons on the basis of national security interests, there is perhaps reason to worry. Recent years offer examples of how national security interests have taken precedence over commitment to collective security and civilian protection. In a few cases, it has even led to the withdrawals from important multilateral agreements in the humanitarian disarmament regimes.
In 2025, Lithuania withdrew from the Convention on Cluster Munitions (CCM), and Poland, Finland, and the three Baltic states withdrew from the Anti-Personnel Mine Ban Convention, commonly referred to as the Ottawa Treaty. The withdrawing states cited the current security environment as the primary reason for this withdrawal. Others have pointed out the contradiction in this: while upholding these agreements is especially important when facing the risk of armed conflict in order to reduce superfluous suffering, the threat of armed conflict seems to have become a justification for withdrawal. The result is that national security is pursued at the expense of civilian protection. Both the Human Rights Watch and the International Committee of the Red Cross note that abandoning the CCM and the Ottawa Treaty threatens civilians lives.
The resilience of multilateral agreements
Luckily, these recent withdrawals are still exceptions. Other agreements limiting states’ ability to use specific weapons, like the Biological Weapons Convention, the Chemical Weapons Convention, the Convention on Certain Conventional Weapons, and the Geneva Protocol on Asphyxiating Gases and Bacteriological Methods of Warfare have not seen any formal withdrawals. The same goes for the general conventions regulating the laws of war: the Geneva Convention and the Additional Protocols. Many international humanitarian agreements have been stable since adoption.
Nevertheless, there is reason to take these few recent withdrawals seriously, as they reflect a waning commitment to previously accepted and entrenched humanitarian norms. International Humanitarian Law (IHL) at large is under pressure. The latest IHL in Focus Report published by the Geneva Academy warns that the “threat to IHL is not yet existential”, however “it is at a critical breaking point”. Is the non-proliferation norm stronger than that? This brings us to the resilience of international norms.
Resilience of international norms
The non-proliferation norm has shaped state decisions and discussions around nuclear issues for many decades, including triggering punitive measures like sanctions to enforce the norm compliance. Research on norm survival suggests that this has likely been fundamental. One study argues that norms degenerate when actors challenge the norm at the same time as there is a lack of enforcement or punishment for norm violations. This means that all signatories to the NPT have an important role to play in encouraging compliance and punishing noncompliance through lawful means.
Another study highlights how individual norms may be protected from external challenges through internal cohesion, institutionalisation, and legal codification – and norms are especially likely to withstand contestation when linked to a larger institutionalised norm cluster. While the non-proliferation norm is codified and institutionalised, the question is whether cohesion around the norm is weakening. According to one argument, norm clusters can be activated as a means for demanding accountability. Several surveys and experiments have also shown that the public cares about international norms when making judgements about foreign policies. This suggests that it might matter how the non-proliferation issue is framed in public discussions. If connected to broader international norms like civilian protection, the chance of norm resilience may increase.
What is at stake in New York?
The 2026 NPT Review Conference may reveal whether collective commitments to nuclear restraint will endure in a geopolitical environment marked by heightened security threats and a growing emphasis on national security and sovereignty. Research on norm survival suggests that norms need to be protected when challenged. This means that it matters not only what the nuclear weapons states say and do in New York, but non-nuclear weapons states have an important role to play. It is paramount that states are willing to stand up and demand a strong commitment to non-proliferation and collective security.
Several surveys and experiments have also shown that the public cares about international norms when making judgements about foreign policies. This suggests that it might matter how the non-proliferation issue is framed in public discussions.