Conference Agenda

In geopolitical conflicts and arms races, nuclear weapons, missiles and space systems are connected in many ways. Risks for international security and stability are difficult to contain by arms control, non-proliferation and disarmament, facing limited motivations and capabilities. Constraints are hard to verify for dual-use potentials and complex interactions among weapon types and delivery systems, air and missile defenses, command and control.

Addressing the complexity of challenges, a framework of verification and security provides a basis to systematically compare nuclear, missile and space arms control. To be effective, agreements needs to be adequately verified to build confidence and assure compliance of State Parties. Preconditions are to define the goals of legal requirements and means of monitoring treaty-limited items and activities, balancing what can and should be verified. Verification is to identify permitted activities and provide early warning of prohibited military capabilities for timely responses minimising security risks. Residual security risks determine the degree of (non-)verifiability, avoiding and detecting intolerable deviations from prescribed activities beyond significance thresholds with reasonable efforts. Related security issues and verification options (national technical means, on-site inspections, safeguards, multilateral vs. bilateral mechanisms) are discussed for existing, past and future arms control agreements of nuclear weapons (NPT, NWFZ, CTBT, TPNW, NWC), missiles (INF Treaty, MTCR, New START, missile ban) and space systems (OST, ABM Treaty, ASAT ban).

The task is to build a firewall against high-risk events which combines technical indicators (capabilities), and contextual factors (security environment): (a) identify high-risk activities, materials and equipment that should be prohibited; (b) determine permissible activities consistent with peaceful applications of technology and know-how; (c) assess in-between activities. Possible criteria for evaluation include benefit-cost-risk effectiveness of verification requirements and instruments; efforts applied to weapons lifecycle stages (from R&D and testing to deployment and elimination), and objects (destructive mechanism, materials, equipments, facilities); breakout scenarios (countermeasures, significance threshold, risk reduction); and uncertainties (dual-use, transparency and confidence-building). Adaptive verification includes stages with different criteria for nuclear, missile and space arms control:

1. Do not have access to high-risk capability, materials or components: Baseline information exchange and data gathering identify the current status of capabilities with reasonable accuracy without proliferating sensitive information. This includes declarations, on-site inspections and remote monitoring of status and location of components, materials, facilities and delivery.
2. Prevent and detect (re-)armament advancing capability to breakout from constraints: prohibited items and activities need to be detected leading to high-risk capability to ensure that legitimate and dual-use capabilities are not converted for such prohibited purposes.
3. Disarm and disinvent existing capability to the degree possible: Disarmament verification monitors agreed pathways to reduce and eliminate risky capabilities by active dismantlement and disposal, conversion or destruction of nuclear facilities.
4. Remove intentions to acquire advanced capability and discourage their reemergence by creating a favourable security environment: Implement political, organisational and societal mechanisms to improve contextual factors of verification, including national ratification and implementation, conflict resolution and institutional regulations, security, public discourses, education and societal participation.

A common challenge with debates on irreversibility of nuclear disarmament is that,

while most agree on its importance, there is little shared understanding of the meaning and implications of the concept. This is true on multiple levels, both in terms of broader goals and outlook and especially in terms of practical steps and approaches.

This paper will argue that irreversibility is intrinsically linked to another concept used in studies of nuclear non-proliferation, namely nuclear latency – the cumulative possession of capabilities needed to develop nuclear weapons. Linking irreversibility and latency is helpful in understanding the role of remaining nuclear capabilities in a disarmed world, the risks they pose, and in identifying some possible approaches to mitigating those risks.

While both latent capabilities and re-armament intentions may exist in concrete forms, neither may be fully discernible to those assessing the risks of that state rearming. There are ways of observing and characterising both, but none are perfect. When faced with this challenge, states might prefer to overestimate the risk of nuclear rearmament than underestimate it and suffer the consequences unprepared.

This predicament resonates with anyone seeking to understand the risks today that an unarmed state may acquire nuclear weapons for the first time. The perspectives involved in this risk assessment are very similar to those that would be involved in assessing the risks of reversible nuclear disarmament. But in a disarmed world, they would be measured from an entirely different frame of reference to the world we live in now. This challenges our imagination to reconsider how latent nuclear capabilities and political intentions might be observed in a disarmed world, and how those observations might inform our assessments of rearmament risks – before, during, and after disarmament.

This paper will draw on existing understandings of capabilities related for nuclear proliferation, including approaches learned from IAEA Safeguards; studies of technology development, weaponisation and militarisation; and considerations on the role of knowledge, and organisational factors. These various aspects of nuclear weapon latency can be combined to form a broad, holistic set of indicators by which states might assess the risks that a disarmed state might disarm. The paper will discuss such a set of indicators and discuss various ways in which they would be relevant in a nuclear disarming and a nuclear disarmed world.

The proposed analytical approach, of looking at irreversibility and latency as deeply related phenomena, and framing irreversibility as the long-term management of risks arising from nuclear latency after disarmament, aims to not only offer a different perspective on the issue of defining and understanding irreversibility, but also to highlight some practical approaches that future work on irreversibility can build on.

An effective implementation and compliance framework is essential for any future nuclear disarmament treaty. Although various elements have been proposed, a comprehensive and cohesive approach that effectively deters rearmament remains elusive. To help address this gap, the VeSPoTec research consortium conducted a 1.5-day tabletop exercise focused on irreversibility and compliance in a regional nuclear disarmament scenario. The exercise brought together experts from international organizations, think tanks, and research institutions to simulate the implementation and verification of a fictional regional nuclear disarmament agreement involving three hypothetical nuclear-armed states. Participants explored the prospective role and mandate of a Regional Verification Organization (RVO) while negotiating tailored, state-specific measures to ensure compliance and irreversibility in the disarmament process.

The simulation was structured around three key components: defining the mandate of the RVO, negotiating state-specific verification strategies, and testing the framework through compliance scenarios. This approach allowed participants to address practical challenges in implementing regionally tailored disarmament agreements while maintaining synchronized progress among state parties with different nuclear capabilities and fissile material stocks.

During the exercise, the ad hoc development of a comprehensive disarmament framework was instrumental in uncovering the key challenges that future efforts will need to address. Participants were tasked with defining a suitable institutional and legal scope of the RVO while reconciling diverging technical approaches to disarmament. Such divergences for instance emerged around how to ensure irreversibility, with experts placing varying emphasis on different components of the nuclear fuel cycle. Because all participants represented nuclear-armed states, proposed verification approaches tended to favour confidentiality and limited oversight. The absence of non-nuclear-armed state perspectives, which might have favoured more intrusive measures, highlighted how stakeholder identify can shape verification design. Interestingly, these constraints allowed participants to explore creative options for increasing the costs of reversal early in the process with minimal interference.

Playing out a scenario based on limited trust between state parties allowed the participants to address what level of confidence might be sufficient to determine compliance. It also stimulated discussions around exit strategies, such as maintaining certain capabilities, ensuring readiness to re-arm, and drawing the line between hedging and legitimate deterrence actions. Moreover, the presence of differing nuclear capacities and fissile material stocks emphasized the complexity of pursuing equal standards in state-RVO agreements.

Beyond identifying such challenges, the exercise fostered dialogue on enhancing treaty robustness – underscoring the role of capacity building, technological cooperation, and selective transparency in fostering mutual trust and balancing disarmament with national security and industrial interests. The diverse backgrounds of participants enabled discussions that blended technical and political perspectives with regional insights from the Middle East, South and East Asia, the United States, and Europe.

Overall, the VeSPoTec tabletop exercise highlights the key challenges in implementing regionally tailored disarmament agreements. By highlighting the need to reconcile divergent perspectives in developing coherent verification frameworks, the exercise provides valuable insights that should inform future disarmament efforts and negotiations.