Kinsella Revisited: Concentration and Diversification in the Post-Cold War Arms Trade Network, 2005–2025

This study extends David Kinsella’s (2003) social network analysis of the international arms trade into the present, asking how far the marketization he anticipated has in fact proceeded. Using the SIPRI Arms Transfers Database for the 2004–2025 period and five annual cross-sections (2005, 2010, 2015, 2020, and 2025), a directed, weighted supplier–recipient network is constructed for each year. Network density, out-degree centrality, group centralization, and the Herfindahl–Hirschman Index (HHI) are used to assess whether the supplier structure has become more dispersed or more concentrated. Contrary to Kinsella’s expectation of progressive marketization, centralization rises from 0.36 in 2005 to 0.54 in 2025 and the HHI rises in parallel, indicating deepening supplier concentration. Beneath this aggregate trend lies a dual dynamic: consolidation at the top of the hierarchy—most visibly the decline of Russia—alongside the entry of new lower-tier suppliers such as Turkiye and South Korea. The findings suggest that concentration and diversification have proceeded simultaneously rather than as uniform marketization.