The United States Army continues to engage in one of the longest periods of combat operations in our nation's history. One result is an increase in the number of people suffering from post-traumatic stress disorder (PTSD). According to the American Psychiatric Association (APA) (2000), a precursor to PTSD is the experience of one or more events that involved actual or threatened death or serious injury to oneself or others. Grossman (2009) argues that an additional factor, the emotional and spiritual response to the killing of another human being, also greatly affects the mental health of returning soldiers. 48 to 65 percent of soldiers returning from Operation Enduring Freedom reported killing an enemy combatant, while 14 to 28 percent reported killing a noncombatant (Hoge, Castro, Messer, McGurk, Cotting, & Koffman, 2004). This article will discuss Grossman's (2009) views on the psychological cost of killing others in combat. The Role of FearNash (2007) points out that soldiers exposed to combat have predictable fears, such as fear of death or serious injury and the loss of fellow soldiers. Several studies have found, however, that these expected fears are not as pervasive as those who have not served in combat might expect (Grossman, 2009). “A soldier's greatest fear is not death but failure, and the shame that accompanies failure. More than anything, warriors fear failing themselves and their leaders and friends when it matters most. Above all, they fear not losing their lives, but their honor” (Nash, 2007, p. 25). Fear in combat can be both a blessing and a curse. Uncontrolled fear can render a soldier ineffective in combat, putting not only that soldier's life... at the center of the paper... 3. doi: 10.1002/jts.20451 Marshall, SLA (1978). Men against fire: the problem of battle command in future warfare. Glouscester, MA: Peter Smith Publishers.Nash, W. (2007). The stressors of war. In C. Figley & W. Nash (Eds.), Combat Stress Injury (pp. 11-32). San Francisco: Routledge. Sherr, M. & Taylor, T. A. (2008). When veterans come home. Journal of Family and Community Ministries, 21(3), 6-16. Retrieved from http://www.baylor.edu/content/services/document.php/145467.pdfSinger, M. (2004). Shame, guilt, self-hatred, and remorse in the psychotherapy of Vietnam veterans who committed atrocities. American Journal of Psychotherapy, 58(4), 377-385.Van Winkle, E., & Safer, M. (2011). Killing versus witnessing in combat trauma and reports of posttraumatic stress disorder symptoms and domestic violence. Journal of Traumatic Stress, 24(1), 107-110. doi:10.1002/jts.20614