A Framework for Measuring Leaders’ Willingness to Use Force

Political leaders’ willingness to use force is central to many explanations of foreign policy and interstate conflict. Unfortunately, existing indicators typically measure one aspect of this general concept, have limited coverage, and/or are not derived independently of leaders’ participation in interstate conflicts. We develop a strategy for constructing measures of leaders’ underlying willingness to use force with data on their background experiences, political orientations, and psychological traits in a Bayesian latent variable framework. Our approach produces measures of latent hawkishness for all national leaders between 1875 and 2004 that offer advantages over existing proxies along multiple dimensions, including construct validity, predictive validity, and measurement uncertainty. Importantly, our statistical framework allows scholars to build upon our measures by incorporating additional data and altering the assumptions underlying our models.