The diagnosis and clinical understanding of posttraumatic stress disorder (PTSD) rests upon the explicit identification of traumatic experiences that give rise to a well-defined constellation of symptoms. Most efforts to investigate the characteristics of these experiences have attempted to specify war zone stressors as objectively as possible. In this study, we add specification of the psychological meaning of war zone stressors to their objective specification. Eleven traumas are organized in terms of four roles that veterans played in the initiation of death and injury; namely, target, observer, agent, and failure. These roles can be ordered in terms of the degree of personal responsibility involved in the initiation of death and injury. The relationships of these roles to current symptomatology were examined in combination with a set of objective measures of war zone stressors. The sample consisted of the first 1709 Vietnam theater veterans who were assessed in a national evaluation of the PTSD Clinical Teams initiative of the Department of Veterans Affairs. Results show that having been a target of others' attempts to kill or injure is related more uniquely than any other role to symptoms that are diagnostic criteria for PTSD. On the other hand, having been an agent of killing and having been a failure at preventing death and injury are related more strongly than other roles to general psychiatric distress and suicide attempts.(ABSTRACT TRUNCATED AT 250 WORDS)