Abstract: Wartime reserve duty can intensify emotional burden and precipitate post-traumatic stress symptoms (PTSS). We investigated whether serving in the reserves during the Iron Swords War and insecure attachment (anxious, avoidant) are associated with higher PTSS, and whether attachment moderates links between war-related stress exposure and PTSS. A quota-matched online sample of Israeli adults ( N = 300; 22–49 years) included 150 reservists called-up since October 7 and 150 not called-up. Participants completed validated measures of attachment (ECR-12), PTSS (PCL-5), anxiety (GAD-7), depression (PHQ-9), and civilian war-related stress exposure. Hierarchical regressions (controlling anxiety and depression) showed that attachment anxiety uniquely predicted higher PTSS across the whole sample. A reserve-service × attachment-anxiety interaction indicated that called-up reservists reported higher PTSS specifically when attachment anxiety was high; the analogous interaction reserve-service × attachment-avoidance was nonsignificant. Greater civilian war-related stress exposure also predicted higher PTSS, and its association with PTSS was stronger at higher attachment anxiety. Findings highlight attachment anxiety as a robust vulnerability factor for PTSS during wartime, especially among called-up reservists and in the context of war-stress exposure. Screening for attachment anxiety and brief attachment-informed supports during reserve service may help target prevention and tailor early interventions for at-risk soldiers and civilians.