In five multi-method studies this dissertation examined how context based morality may explain increased incidence of combat related psychological difficulties among US service personnel. We were particularly interested in the relationship between causing harm to others and moral self-perceptions and related emotional consequences. In studies 1 and 2 we found that our samples of Iraq and Afghan war veterans reported that a soldier would feel increased levels of guilt and shame and negative moral judgments of the self when they return home and reflect on incidents of harm that may have occurred during their deployments. These two studies were supported by three short experiments showing that different moral judgments of harm were made depending on whether the harm doing was interpersonal or intergroup. Interpersonal harm doing was judged more harshly than intergroup harm leading us to believe that while in combat harm doing had minimal consequences on the self-perceptions and emotions of a soldier and that when they returned home to civilian life where interpersonal moral standards are more prevalent their self-perceptions and emotional wellbeing was affected by their prior conduct.