Distinguishing the Effects of Life Threat, Killing Enemy Combatants, and Unjust War Events in US Service Members

Although previous studies have identified behavioral health risks associated with combat exposure, it is unclear which types of combat events are associated with these risks, particularly regarding contrasts among the risks associated with life-threatening experiences, killing combatants, and exposure to unjust war events, such as killing a noncombatant or being unable to help civilian women and children. In the present study, we examined surveys from 402 soldiers following deployment (i.e., baseline) and again 13 months later (i.e., Year 1). Regression analyses were conducted across a range of behavioral health (e.g., posttraumatic stress disorder, depression, suicide ideation, anxiety, somatic, insomnia, aggression) and benefit-finding measures, each controlling for two combat event categories while assessing the predictive utility of a third. The results suggested that life-threatening events were associated with poor behavioral health at baseline, relative risk (RR) = 10.00, but not at Year 1, RR = 2.67. At both baseline and Year 1, killing enemy combatants was not associated with behavioral health, RRs = 1.67-3.33, but was positively associated with benefit-finding, RRs = 26.67-40.00. Exposure to unjust war events was associated with a transdiagnostic pattern of behavioral health symptoms at baseline, RR = 40.00, and Year 1, RR = 23.33. Overall, the results suggest unjust war event exposure is particularly injurious, above and beyond exposure to other combat-related events. Future research can build on these findings to develop clearer descriptions of the combat events that might place service members at risk for moral injury and inform the development of assessment and treatment options.