Just war thinking serves a social and psychological role that international law cannot fill. Law is dispassionate and objective, while just war thinking accounts for emotions and the situatedness of individuals. While law works on us externally, making us accountable to certain people and institutions, just war thinking affects us internally, making us accountable to ourselves. Psychologically, an external focus leads to feelings of shame, while an inward focus generates feelings of guilt. Philosophers have long recognized the importance of these two moral emotions. Recently, psychologists have found that feelings of guilt are linked to positive social outcomes, such as the desire for reconciliation and reparation, while shame generates anger and hostility. Just war thinking, as an inward-looking tradition, has a special relationship with guilt. By focusing on moral emotions, just war thinking can move beyond the law in four ways, by developing an ethic of accountability, by providing a foundation for addressing moral injury, by providing a common language for discussing the costs of war, and for identifying ethical problems in radically new contexts.