Rising suicide rates are an increasing concern among military personnel. The interpersonal-psychological theory of suicide proposes that three necessary factors are needed to die by suicide: feelings that one does not belong with other people, feelings that one is a burden on others or society, and an acquired capability to overcome the fear and pain associated with suicide. The current study tests the theory's proposal that acquired capability may be particularly influenced by military experience, because combat exposure may cause habituation to fear of painful experiences such as suicide. Utilizing clinical and nonclinical samples of military personnel deployed to Iraq, results of the current study indicate that a greater range of combat experiences predicts acquired capability above and beyond depression and post-traumatic stress disorder symptoms, previous suicidality, and other common risk factors for suicide. Combat experiences did not, however, predict perceived burdensomeness or thwarted belongingness. The authors discuss how combat experiences might serve as a mechanism for elevating suicide risk and implications for clinical interventions and suicide prevention efforts. © 2010 Wiley Periodicals, Inc. J Clin Psychol: 66:1–13, 2010.