• Intergroup Conflict;
  • Group Norms;
  • Interdependence;
  • Collective Vulnerability;
  • Social Representations;
  • War

This paper investigates the effects of war experiences across three different levels (individuals, groups, and contexts) on moral judgments related to violations of humanitarian norms. Competing hypotheses derived from different theoretical perspectives are empirically evaluated. Social psychological studies of war traditionally highlight a reversal of morality and group norms justifying violence against outgroups. Rationalistic models insist on the importance of realistic costs on the choice of individuals. As a complement to these traditions, we suggest that situations in which risks are generalized across group boundaries tend to provoke a strengthening of principles, such as humanitarian norms, that enable the protection of the material and symbolic integrity of a community. Multilevel analyses of the international People on War survey dataset (N = 8,121) show that support for the ingroup's struggle, at both individual and group levels, predicts stronger justification of violence. Simultaneously, at the context level, generalization of war-related risks predicts stronger condemnation of violations of humanitarian principles. These findings are consistent with a collective vulnerability model and, only in part, with the intractable conflict model.