Exploring the speed of change: European defence budgets in an age of danger

This essay explores the theme of speed of change in defence budgets for nations that experience violent deteriorations in their security environments, with a focus on responses to the Russia-Ukraine war. The analysis is innovative in exploiting both long-term historical data and especially collected national data on budget revisions within fiscal years. Recent increases in European defence burdens are comparable to those of European states during the 1930s. The increases are stronger for states that are geographically closer to Russia and, among those states, stronger for larger states. Smaller states tend to choose lower defence burdens, whether or not they are in an alliance. These findings challenge the traditional understanding of free riding within alliances and imply a need for defining new types of state behaviour. Two new behaviours are posited: binding for the case of Poland, and antagonistic free riding for the case of Hungary.