The forthcoming article “Complementarity in alliances: How strategic compatibility and hierarchy promote efficient cooperation in international security” by J. Andrés Gannon is summarized by the author below.
How can defense alliances effectively harness the benefits of collective action when faced with significant coordination challenges and the risks of opportunism? This study investigates the conditions under which states can overcome these inherent difficulties to achieve efficient cooperation in international security. I argue that alliances characterized by high strategic compatibility and a hierarchical structure are better equipped to minimize opportunism and coordination costs. This, in turn, facilitates an efficient distribution of defense capabilities among member states, fostering complementarity and a functional division of labor rather than promoting redundant military investments.
To assess this theoretical framework, I develop a novel network-level measure of the division of labor within alliances. This measure is applied to an extensive dataset of national military capabilities spanning from 1970 to 2014. The empirical analysis also incorporates improved measures of strategic compatibility—defined as the extent to which states concur on the nature of the international threat environment—and hierarchy, understood as an asymmetric distribution of influence over security decisions within the alliance.
The findings indicate a robust positive association: alliances with high strategic compatibility and greater hierarchy exhibit a significantly higher division of labor. This suggests that shared security interests and centralized decision-making structures within an alliance are crucial factors that mitigate the inherent costs of collective action, enabling a more rational and efficient allocation of defense responsibilities.
This research offers several contributions to the understanding of international security. It clarifies the interaction between alliance structures and armament policies, demonstrating that the distribution of military capabilities within an alliance is shaped by the alignment of security interests and the nature of its decision-making framework. Furthermore, it introduces complementarity as a distinct mechanism through which alliances can enhance the efficiency of defense spending and collective security outcomes. Finally, the study challenges the conventional view of states as undifferentiated “like-units” in the international system by providing evidence of functional differentiation emerging from cooperative security arrangements. These insights underscore the importance of alliance design in promoting efficient and effective international security cooperation.
About the Author: J. Andrés Gannon is an Assistant Professor of Political Science at Vanderbilt University and a Faculty Affiliate at the Data Science Institute. Their research “Complementarity in alliances: How strategic compatibility and hierarchy promote efficient cooperation in international security” is now available in Early View and will appear in a forthcoming issue of the American Journal of Political Science.
Speak Your Mind