The Ideational Logic of Alliance Network Embeddedness: Explaining F-35 Cooperation

Abstract What drives some U.S. partners to gain access to advanced weapons cooperation such as the F-35 program, while others do not? Taking a relational and ideational scope, I argue that participation is not driven by strategic dependence but by ideational affinity operating through Security Alignment Network Embeddedness (SANE). States with liberal-democratic compatibility are selectively incorporated into dense, central positions within the U.S.-led security network, and this embeddedness – rather than realist security demands – creates both the opportunity and the willingness to enter high-cost technological cooperation. Using social network analysis to construct the SANE index, as well as panel-based structural measures for 130 states (2001–2023) within a mediation framework, empirical analysis shows that ideational affinity strongly predicts SANE, SANE in turn predicts F-35 participation, and affinity’s effect is fully mediated through embeddedness, whereas strategic dependence has no systematic influence. A placebo test on the F-16 fighter and additional robustness checks confirm that this mechanism applies only to institutionalized advanced cooperation, not to general arms sales. The findings show that advanced weapons function as signals and symbols that consolidate hierarchy through embedded network relations.