Less Is More? Shifting Power and Third-Party Military Assistance

In contexts as diverse as civil war interventions, alliances, and military coalitions, states often militarily assist proteges to counteract unfavorable power shifts. Existing theoretical work finds that such assistance mitigates commitment problems and reduces the probability of war. We develop a model that captures this but also includes information asymmetries. In many cases, overcoming the commitment problem encourages the protege to take greater risks in bargaining, thereby increasing the probability of war due to incomplete information. Using mechanism design, we show that in some cases, no feasible transfer can reduce the probability of war to zero. More broadly, our results indicate that encouraging policymakers to further expand military assistance can backfire despite empirical relationships that may appear otherwise.

Automated summary

In various contexts, such as civil war interventions and alliances, states often assist their proteges militarily to counter unfavorable power shifts. Previous studies suggest that this assistance mitigates commitment problems and reduces the likelihood of war. However, our model incorporates information asymmetries and shows that overcoming the commitment problem may lead to increased risks and incomplete information, thus raising the probability of war. Mechanism design analysis reveals that in some cases, no feasible transfer can completely eliminate the risk of war. Overall, our findings caution against expanding military assistance based solely on empirical relationships.