While the motivations of individuals to become foreign fighters have been at the forefront of academic interest, an important motive—revenge—has so far remained under-researched. Drawing on the case study of pro-Ukrainian Chechen foreign fighters self-deployed in the ongoing Russo-Ukraine War, this article seeks to fill the gap in the extant literature by identifying and conceptualizing revenge. This article posits that two intertwined motives—revenge for perceived historical injustices and revenge for personal wrongs—have played an important role in motivating Chechens to become foreign fighters in the ongoing Russo-Ukrainian war. This article suggests that while revenge might be a potent driving force of foreign fighting, its appeal may be stronger in the cultures of honor with the persisting notion of retaliation.