Reputation, Symmetry, and Alliance Design

There is significant variation in the design of military alliances but scholars currently do not have a good understanding of when members choose one design over another. This article argues that alliance design is motivated, at least in part, by reliability considerations. If concerns about opportunism are high—when prospective members have a history of alliance violation—the signatories should be more willing to implement costly reliability-enhancing provisions such as greater precision in when alliance obligations apply, issue linkage, and increased institutionalization. However, this should be more likely in symmetric alliances where members of similar power levels rely on the support of their partners and thus sensitivity to opportunism is high. In asymmetric alliances, major powers may not find reliability-enhancing provisions necessary and minor powers, who do worry about the reliability of their partners, are unable to force more costly alliance designs given their limited bargaining power. The theoretical expectations are tested using data on bilateral alliances between 1919 and 2001 and the results are generally supportive of the hypotheses.