The unremitting conflict between Israel and its neighbors has created a situation that often exposes soldiers to the repeated stress of a number of wars. Studies conducted by the Research Branch of the Mental Health Department in the Israel Defense Forces Medical Corps have focused on the long-term mental health effects of such trauma. This article brings together the findings of a recent series of studies that examine the effects of both single and repeated exposure to the stress of battle, in terms of: (a) psychiatric breakdowns on the battlefield (Combat Stress Reaction); (b) enduring symptomatology (Posttraumatic Stress Disorder); and (c) the reactivation of previous traumas. Additional findings highlight the transgenerational effects of trauma as evidenced in the susceptibility of offspring of Holocaust survivors to combat stress reactions.