The concept of the self-traumatized perpetrator emerged in the United States in the 1970s, in response to moral confusion associated with the Vietnam War. By the 1980s, self-traumatized perpetrators composed a clinical sub-population of American veterans diagnosed with posttraumatic stress disorder (PTSD), and were the subject of psychological, psychophysiological, and epidemiological research. The self-traumatized perpetrator is distinguished from other cases of PTSD in that he is said to be the psychological victim of his own violence and unlawful behaviour. The self-traumatized perpetrator is an example of a psychiatric disorder that emerges within an 'ecological niche' formed by discrete historical conditions, political interests, and widespread concern regarding national social identity. When this ecological niche disappears, so does the diagnostic entity – in this case, the self-traumatized perpetrator – as a recognized medical, forensic, and cultural phenomenon. This chapter outlines the history of the self-traumatized perpetrator from its beginning in post-Vietnam America to its puzzling after-life in present-day Iraq.