In light of current modifications in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) diagnostic criteria for posttraumatic stress disorder (PTSD), this study aimed to revalidate well-known PTSD risk factors related to terrorism and war in Israel, namely, proximity to the Gaza Strip, dissociative symptoms, acute stress disorder (ASD) symptoms, and social support. One hundred and sixty Israeli civilians were assessed during the 2014 Israel-Hamas war at 2 time points: 1 week after the beginning of the operation (t1) and 1 month after initial evaluation (t2), using the DSM-5 PTSD Symptom Levels Scale (PSLS; Gil, Weinberg, Or-Chen, & Harel, 2015). A paired t test analysis showed significant reduction in the respondents' posttraumatic stress symptoms (PTSS) 1 month after the initial assessment point. A structural equation model (SEM) showed that higher ASD symptoms at t1 and higher dissociative symptoms at t2 increased the risk for PTSS at t2. Conversely, higher peritraumatic dissociation at t1 decreased the risk for PTSS at t2. Proximity to the Gaza Strip, and social support, failed to demonstrate significant association with PTSS at t2. DSM-5 PTSS 1 month after prolonged traumatic exposure are strongly associated with high ASD symptoms at 1 week as a risk factor; high levels of peritraumatic dissociation at 1 week as a protective factor; and high levels of dissociative symptoms at 1 month as a risk factor. Theoretically and clinically the findings of the study further suggest that ongoing massive terrorism and war cannot be viewed or treated as identical to other traumas.