Shades of verification: three benchmark understandings of verification in NPT review cycles (2003–2022)

Abstract What kinds of different understandings of “verification” co-exist in the non-proliferation treaty (NPT) process? In this article, we address this question through a qualitative analysis of 448 working papers on nuclear verification submitted to the NPT’s Preparatory Committees (PrepComs) and Review Conferences (RevCons) between 2003 and 2022. First, we mapped the social networks of actors—organisations, institutions, and States—who discuss and promote different views on verification. Next, we examined the verification conceptions advanced by these actors and, by induction, delineated three ideal-types, which we call benchmark understandings of verification: (1) Technocentric: emphasising technical measures, methodologies and innovations; (2) Legalistic: prioritising clear legal commitments and procedural obligations before verification activities commence; (3) Contextual: linking verification activities and enforceable commitments to developments in the broader geostrategic environment. By identifying and comparing these perspectives, this article contributes to efforts to foster dialogue among States and to identify areas where verification can help bridge differences and advance progress across all pillars of the NPT. Beyond the field of nuclear politics, this article also contributes to the broader discussion of ideal types in International Relations theory, and with an analytical differentiation between “perspectives” and “understandings”.