The rise of armed conflict around the world begs for renewed reflection on what constitutes just war. Modern just war discourse is characterised by a very formal approach to war ethics. Issues of character, internal disposition and virtue are rarely addressed, while the Augustinian tradition's ad bellum criterion of right intention is no longer accepted as a necessary requirement for going to war. It is argued that notions that belong to the assessment of character are not necessarily relevant to the assessment of actions. Instead, current discourse is characterised by an effort to formulate clear rules that can be easily applied in conflict situations. This article argues that issues of character, virtue and right intent are important for a war ethic, because actions that are based on wrong intentions will inevitably distort a cause. If a just cause is not grounded in sound intentions the underlying reasons for characterising a cause as just disappear. In response to the lack of virtue-ethical reflection in current just war discourse, the article attempts to retrieve some of the earlier moral roots of just war discourse by discussing the contributions of Augustine and Thomas Aquinas. Their works are remarkably relevant in addressing the current weakness in just war discourse, because they enable us to expand the scope of ethical deliberation on just war to include virtue. The first section discusses the contribution of Augustine, the second analyses Aquinas's perspectives on just war, while the third evaluates the importance of these exponents for modern just war discourse. The last section concludes by indicating how virtue-ethical criteria might inform norms for warfare. The so-called ‘war on terror’ is used as a point of reference to illustrate the value of applying virtue-ethical criteria to the discourse on just war.