The article presents a course of treatment and psychotherapy of a 38 y.o. veteran of the Polish War Contingent, who took part in military missions in Lebanon and Afghanistan (the sixth turn). Patient had a traumatic experience, i.e. he has been shot on the helmet. Since then he has had a history of a long‑term and intensifying behavioral change, manifesting in aggressive behavior and violence. The authors, retracing the traumatic experience frame by frame, discuss the psychological mechanism of dissociation. The article describes attempts of a war trauma psychotherapy, which were demanding both for the patient and the clinical psychologist/psychotherapist. The article tries to explain aggressive behaviors in veterans based on the identification with the aggressor defense mechanism. At the end, the authors give a few remarks on the clinical experience in PTSD diagnosis in veterans with a high level of aggressive behavior and anger.