Three major achievements for nuclear diplomacy of the last decades – the JCPOA in 2015 which provided for a verified way to dismantle the conditions for nuclear weapons in Iran, the de-nuclearization of Ukraine in the Budapest Memorandum of 1994, and the New Start, which successfully decreased the number of warheads and provided ways to monitor the reduction – are now in disarray. The present situation indicates a decline in the role of nuclear diplomacy, supplanted increasingly by the use of military force.

It is against this stark background that diplomats will soon gather in New York to review the implementation of one of our strongest international agreements, the nuclear non-proliferation treaty (NPT).

Can research on nuclear diplomacy help inform the negotiators meeting in New York? In a recent book, Ulrika Möller and myself have brought together a group of leading scholars to take stock of what we know from research about the conditions for making nuclear diplomacy more effective. Among many insights, three lessons can be highlighted.

Build more effective coalitions

In order to manage this complexity, coalition-building – where different countries join forces in order to take initiatives or advance certain goals – is often crucial. Effective coalition-building requires the identification of common interests. Particularly important are coalitions that can bridge the divides in the nuclear bargaining landscape: between North and South, and between the nuclear haves and the have-nots.

The chair can play an important role

The chairs – an individual representing a country – in charge of the proceedings of multilateral negotiations, play an important role in designing effective formats and trying to bridge incompatible claims and positions. Chairs can contribute to more effective processes by building trust, disseminate and spread information, and help to build better working relationships among negotiators. Chairs are, as previous research demonstrate, not necessarily a decisive factor, but still have an important role to play.

This year the review conference will be chaired by Ambassador Do Hung Viet from Vietnam. Vietnam is a particularly interesting country in this context. It is a bridge country, which does not fully align with either the US or Russia and it has a complicated history with both. One of the key challenges for the overall negotiation landscape is the stalemate in the blame-game between China and the US: the US blames China for being the country that is most rapidly expanding its nuclear arsenal without being bound by any arms control, while China points to the total number of American warheads which far exceeds China’s. This affects the space for multilateral negotiations as well and the NPT RevCon will be affected by this polarization. Negotiators may take lessons from the climate negotiations, where similar dynamics have occurred, but where parties eventually managed to find a formula for including China in the negotiated framework. Vietnam could potentially play a vital role in trying to unlock this problem.

Protect previous achievements

Arms reduction, regulation and non-proliferation in the area of nuclear weapons take long time to negotiate. Nuclear negotiations reflect and re-enforce great power status and global politics as well as acute security concerns. Moreover, negotiations are based on often highly detailed technical knowledge in order to be feasible, in particular when it comes to verification. For example, the Joint Comprehensive Plan of Action (JCPOA) built on over a decade of several different diplomatic attempts to resolve the concerns with weaponization of Iran’s nuclear program. The agreement emerged from almost two years of sustained negotiations, from 2013 to 2015, between Iran and P5+1.

The NPT is the cornerstone of the international nuclear diplomacy architecture and needs to be both protected and developed. After the New Start agreement has expired, there is no agreement through which the nuclear weapons powers implement (even if only gradually and partially) arms control and disarmament, in line with the obligations that they have according to the NPT.

In sum, the current crisis in nuclear diplomacy underscores both the fragility of past achievements and the urgency of renewed cooperation. While agreements have unraveled and geopolitical tensions intensified, research shows that effective leadership, the protection of hard-won frameworks, and strategic coalition-building can still make a difference. As negotiators convene to review the NPT, these lessons also offer a reminder that meaningful progress in nuclear diplomacy remains possible—the history of nuclear diplomacy tells us that difficult times have also provided urgency to act.