Irreversibility of Nuclear Disarmament 

Summary of a side event at the NPT Preparatory Committee 

Vienna International Centre, 3 August 2023 


Opening Remarks 

Ambassador Aidan Liddle, the UK’s Permanent Representative to the Conference on Disarmament, and Ambassador Susan Eckey, Permanent Representative of Norway to the United Nations delivered the opening remarks to the side event. Ambassador Liddle expressed his hope that irreversibility may reframe the disarmament conversation to envision practical steps towards a disarming world. Ambassador Eckey advocated the importance of building dialogue among States Parties on the concept of irreversibility, in addition to the dialogue currently taking place in civil society. Both ambassadors agreed on the importance of achieving a common interpretation of irreversibility, and continuing to fund research to examine the subject in all its technical, legal, political, economic and social aspects. However, Ambassador Liddle especially emphasised that reaching a shared understanding of irreversibility is not a prerequisite for moving forward with disarmament. 


Panel Discussion 

The panel was opened by Mr Alberto Muti, Co-Programme Director for Verification and Monitoring at VERTIC (also serving as moderator). In his speech, Mr. Muti noted that while complete irreversibility may be impossible, it is possible to identify practical approaches to make re-armament more difficult and manage the risk of nuclear weapons re-emerging in a disarmed world. One of the tools to do so is verification, and Mr. Muti highlighted some of the findings from an upcoming VERTIC article, including key qualities of verification processes to support irreversibility. Such processes should be designed to be well understood and widely trusted by their participants, and should have timely detection of re-armament attempts as a priority, in order to give the international community opportunities to respond to violations. A robust verification regime can also help build the confidence states need to join disarmament agreements in the first place, and offers opportunities for participating states to engage in voluntary transparency, as a way to signal their support for disarmament norms. Mr Muti also discussed another VERTIC project on the topic, in its initial phases, which frames irreversibility as a way of managing nuclear latency.  

Dr Joelien Pretorius, Associate Professor at University of the Western Cape, was the next to speak on the panel. Using South African nuclear disarmament as a case study, she proposed three phases which comprise the process: initial conditions, the critical juncture, and self-reinforcement. During the self-reinforcement phase, Dr Pretorius argued that path dependency serves to ‘lock-in’ disarmament and contribute to its irreversibility. She explained how path-dependency can ‘lock-in’ behaviour through both utilitarian (increasing economic and political returns for staying the course) and normative (moral restructuring) mechanisms. Dr Pretorius spoke as well about the importance of recognising the initial conditions and critical junctures which create windows of opportunity to disarm, especially in cases where unilateral efforts could lead to ‘coordination effects’, further incentivising steps towards disarmament.  

Ms Irma Arguello, Director of NPSGlobal Foundation, then discussed political contexts around irreversibility. She recommended that irreversibility dialogue should not be left solely to nuclear weapons-possessing states, and highlighted that non-nuclear weapons-possessing states must also be included in order to achieve truly universal understanding of practical disarmament steps, including through multilateral initiatives. Further, Ms Arguello noted that latency is implicit in irreversibility, thus researchers should also begin exploring how to prevent theoretical knowledge from ‘leaching back into the material world’. She listed the following key conditions for irreversible steps towards disarmament: political will, strong incentives, addressing low-hanging fruit first, and high visibility. Finally, Ms Arguello ended on a silver lining – discussion of irreversibility within fraught contexts, such as the current security environment, is necessary to ensure related agreements are built on a shared understanding robust enough to survive future crises. 

Rounding out the panel, Ms Gaukhar Mukhatzhanova, Director of the International Organizations and Nonproliferation Program at VCDNP, spoke on the balance of technical and political work on irreversibility and the visualisation of an ‘end-state’ goal. Ms Mukhatzhanova pointed to VERTIC’s 2011 report on irreversibility as a good starting point for technical discussions due to its focus on the cost and difficulty of rearmament steps, and its framing of irreversibility as a spectrum. However, her remarks acknowledged that irreversible disarmament cannot be achieved through purely technical means, and political, legal and normative conditions must fill the ‘end-state’ gap for assuring irreversibility and managing an agreed-upon level of latency. To this point, she emphasised the eventual need to conceptualise various disarmament ‘end-state’ goals and come to a shared understanding on which one to pursue. Possible ‘end-states’ will lay on a spectrum of nuclear latency, with complete prohibition of all nuclear activities at one extreme. Ms Mukhatzhanova noted that while reaching such understanding is not necessary to take initial steps, it must eventually be agreed upon.  



After the panelists spoke, discussion was opened up to questions and comments from the audience. Louis Reitmann from VCDNP asked if there is a difference between the technical and path dependency theories of irreversibility. He also wondered whether reliance on deterrence theory is an obstacle to changing the balance of incentives between armament and disarmament, and if it would be easier to allow the NWS to pursue reversible disarmament first. In response, Ms Mukhatzhanova referred to Amy Woolf’s work distinguishing the irreversibility of a process from the irreversibility of outcome, as illustrated by elimination of weapons under arms reduction agreements. Mr Muti agreed and pointed to France’s dismantlement of its Marcoule and Pierrelatte sites as a case study of irreversible individual steps that are not linked to a broader goal of irreversible disarmament. Responding to Mr Reitmann’s question on incentives, Ms Arguello reminded the audience that we tend to assume perfect rationality of decision makers in cost-benefit analysis, which is often not the case. Dr Pretorius added insight into the benefits of coordination effects in the agreement to irreversibly destroy chemical weapons stockpiles.  

Dr Nick Ritchie from the University of York followed on with another salient question: if maximising irreversibility entails dismantling not just physical structures, but also ideological ones, are arguments attacking the legitimacy of nuclear weapons part of efforts towards irreversibility? Mr Muti noted that interesting research on normative aspects of irreversibility is taking place – including by Dr Ritchie himself. 

Ambassador Nozipho Mxakato-Diseko of South Africa shared her perspective on achieving commonality of intent towards revolutionary changes, in the light of South Africa’s experience of ending apartheid. She acknowledged the difficulty of both the democratisation and disarmament processes, and noted parallels in Nelson Mandela’s grand strategy of small steps in critical areas to achieve irreversible democracy. The ambassador recommended focusing on a similar strategy for global disarmament, recommending steps such as productive NPT review conferences while allowing for delicacy and space in pursuit of the overarching objective, noting that all parties need to feel secure in order to proceed. 


VERTIC would like to thank the panellists for their contributions and the United Kingdom’s Foreign and Commonwealth Development Office and the Norwegian Ministry of Foreign Affairs for their support of the side event and broader research on irreversibility.