The Influence of Religion on Armed Conflict Onset

This dissertation examines the effect of religion on the use of military force by states against other states. Despite a growing body of literature on religion and/in international relations, the topic remains under-studied and under-theorized; most of the literature focuses either on conflict associated with religious differences, or on religious identity or culture as a driver for civil and other non-state wars. In contrast, I treat religion as an effect on the ideological characteristics of a state, and argue that religious ideas influence the outcomes of war and peace. I argue that religion wields its effect through three media: religious scripture, the priesthood (or more precisely, the writings of the priesthood), and historical narrative. Through these media, each religion generates a war ethic that influences the decisions of states to use military force or not. I measure that influence through a series of variables which capture the religious identities of chief executives of states, the preference for a particular religious category held by governing regimes of states, and the religious demographics of the citizenries of states. Having done this, and having controlled for the other conventional factors, I find that (1) religion does influence a state's propensity to use force against other states, and (2) different religions have different effects. I find that Christian states are less likely to initiate interstate armed conflicts than non-Christian states, Muslim states are more likely than non-Muslim states, and Buddhist states are no more or less likely than non-Buddhist states. In other words, Christianity has a negative effect on a state’s propensity to use force, Islam a positive effect, and Buddhism no effect