From Ideology to Goals: A New Conceptualization and Measurement of Political Alignment in Rebel Alliances

This research note distinguishes between rebel ideology and political goals to improve explanations of alliance formation during civil war. While existing studies emphasize ideological similarity as a driver of cooperation among violent nonstate actors, they rely on binary or categorical labels that obscure important variation in what rebel groups actually seek to achieve. I argue that political goals—defined as the substantive outcomes groups pursue in a post-conflict order—are multidimensional and continuous, and thus require a different measurement approach. I develop a Bayesian multidimensional ideal point model that estimates rebel group goals from expert-coded indicators of group characteristics. I then incorporate these estimates into a unified framework to predict alliance formation. The results show that goal proximity is a strong and consistent predictor of cooperation, outperforming commonly cited factors, such as shared foreign sponsorship and military capacity. This approach improves out-of-sample predictive accuracy and clarifies theoretical expectations about alignment. More broadly, it contributes to ongoing efforts to refine the measurement of latent actor preferences in conflict research.