The clichéd "Clash of Civilizations" , which assumes a religious basis to competing cultural ensembles, has received surface reinforcement from recent events. So has the Assmanian thesis of a "curse of Monotheism". And more generally, how to account for the intensity with which humans often kill -- now and in the past? The more interesting historical question is whether a religion makes a difference when it comes to warfare, its motivations, its conduct, its limitation, its experience, its commemoration. Or are these dimensions of war principally shaped by so-called anthropological universals? The answers pass through comparative analysis. At the CEU IAS, my principal agenda, embedded in a wider one involving five societies, would be to write a preliminary study comparing civil war in the premodern West and medieval Japan, exploring their religious dimensions, when present.