To explore a novel model for war-related posttraumatic stress disorder (PTSD) symptomatology including emotion regulation processes, namely experiential avoidance (EA) and uncompassionate self-responding (USR), mediating the impact of childhood threat memories, combat exposure distress, combat and noncombat threats, and peritraumatic depersonalization/derealization (PDD) on PTSD symptomatology. A sample of 650 male Portuguese Overseas War veterans filled self-report instruments. The model explained 59% of the variance of PTSD symptomatology. Both EA and USR mediated the effects of noncombat threats and PDD on PTSD. Additionally, EA mediated combat exposure distress and USR mediated childhood threat memories. Combat exposure distress, combat and noncombat threats, and PDD showed direct effects on PTSD symptomatology. The findings help to better understand the relationship between predictive factors of war-related PTSD in clinical and research settings, providing novel insights on the effects of combat exposure distress, and the different effects of combat and noncombat-related threats on PTSD.