ARMS, ALLIANCES, AND SECURITY TRADEOFFS IN ENDURING RIVALRIES

Recent work on alliances, notably Walt (1987, 1988), emphasizes that s tates form alliances to balance against threats. In this article, I co nstruct a constrained optimization model to demonstrate that a mix of arms and alliance is a better characterization of states' security pol icies. States choose the mix according to the relative costs associate d with each approach, as well as the level of their allies' military c apabilities. I test the predictions of the model using econometric ana lysis of data on France and Austria prior to World War I and Israel an d Syria in the contemporary period. The empirical results illustrate s tates' tendencies to rely on their allies' arms when allied support is relatively cheap and their allies are militarily strong; whereas they tend to rely on their own capabilities when allied support is relativ ely costly and their allies are militarily weak.