Right-wing authoritarianism (RWA) and social dominance orientation (SDO) are associated with the approval of war as a political intervention [McFarland, 2005]. We examined whether the effects of RWA and SDO on war support are mediated by moral-disengagement mechanisms [i.e., responsibility reduction, moral justification, minimizing consequences, and dehumanizing blaming victims; Bandura, 1999] and whether the ideologies use the mechanisms differently. Our data were consistent with the possibility that minimizing consequences (Study 1) and moral justification (Study 2) mediate the effects of RWA and SDO on approval of war. Both ideologies were positively associated with all moral-disengagement mechanism though more strongly so for RWA. Comparisons within ideologies suggest that RWA was most strongly associated with moral justification and SDO was most strongly associated with dehumanizing blaming victims. We discuss implications and limitations. Aggr. Behav. 36:238-250,2010. (C) 2010 Wiley-Liss, Inc.