Exposure to war is a severe traumatic experience with disastrous mental health effects. This study examined the mental health among 5,560 residents in 11 countries worldwide at different geographic distances from the epicenter of the Russian-Ukrainian War (RUW). An online questionnaire assessed war-related variables (e.g., personal experiences with RUW, perceived concern and threat), previous life stress experiences, and mental health (i.e., resilience, anxiety, depression, perceived stress, ICD-11 PTSD, and CPTSD). Results showed regional differences. Ukrainians had the worst mental health indices, followed by participants in the bordering countries, and then by those in the distal ones. War-related variables were associated with worse mental health. The common predictors for PTSD and CPTSD were previous mental disorder, anxiety, and perceived stress, whereas unique predictors were also found (PTSD: female gender and impact of news on mental health; CPTSD: being single, overall impact of war on mental health, sum of lifetime traumatic experiences, resilience (inversely), and depression). Given the continuing uncertainty about the threat of war for many of the nations in this study, findings suggest the need for practitioners to support concerned populations.