In his colloquium, entitled Revenge Wars, Uri discussed how in the wake of widescale deadly attacks, desire and support for military revenge are prevalent. Rather than dismissing it as due to ignorance, moral depravity or heat of the moment, he proposes that support for military revenge is more charitably understood as support for a‘retributive revenge war,’ aimed at inflicting deserved harms on the enemy without punitive authority. Revising McMahan’s conception of just cause, I argue that a retributive revenge war could in principle be just, if deserved harms could be good independently of their consequences. I then consider several reasons to think that in practice, such wars are unlikely to be just, and submit that the strongest reason is that they would be disproportionate, because the goodness of deserved harms is unlikely to outweigh the evils of war. But if their chances of meeting this requirement are non-negligible, such war could in practice be just.