The psychology of interstate rivalries: leaders' beliefs and the dynamics of conflict and cooperation

Abstract This article explores how the beliefs of political leaders in rival dyads shape the dynamics of cooperation and conflict in Latin American spatial rivalries, focusing on the cases of Bolivia, Chile and Peru. Using the operational code analysis framework, it investigates how leaders' beliefs about the political landscape and their strategic preferences correlate with periods of cooperation and escalation. By incorporating political psychology, the article goes beyond structural factors to assess how leaders' beliefs influence interstate relations. It analyses the cases of five presidents from Chile, Bolivia and Peru during key periods of cooperation and tension between 2006 and 2014, highlighting the importance of considering leaders' beliefs on both sides of a rivalry. The findings suggest that cooperative periods have occurred when rival leaders share positive and congruent beliefs and favour collaborative strategies. In contrast, escalation has taken place when leaders exhibit divergences in their views, particularly when one leader harbours negative perceptions and adopts a more hostile stance. Drawing on frustration–aggression theory, the article also examines how leaders' perceived control over political events shapes their foreign policy decisions. By focusing on the psychological drivers of rivalries, this article not only deepens our understanding of minor power conflicts in Latin America but also contributes to the broader literature on rivalry dynamics, offering insights into the micro-foundations of International Relations and how leaders' beliefs shape long-term conflict and cooperation in non-militarized contexts.