In their contributions to the symposium “Just War and Unjust Soldiers,” Michael Walzer, Jeff McMahan, and Robert O. Keohane add greatly to our understanding of how best to study and apply just war doctrine to real-world conflicts. We argue, however, that they underestimate both the degree to which the American public seeks revenge, rather than just reciprocity, and the extent of popular acceptance of violations of noncombatant immunity by soldiers perceived to be fighting for a just cause. We call on empirical political scientists, lawyers, psychologists, and historians to engage with moral philosophers and political theorists in debates about the influence of just war theory and the laws of armed conflict.