This paper delves into the dynamic relationship between where the conflict takes place and public support for military intervention in the context of friendly countries facing aggression. Focusing on the recent surge of Western assistance to Ukraine and the growing concerns about China–Taiwan tensions, our experimental study, conducted in Japan and Czechia, investigates whether regional proximity influences individuals’ willingness to endorse the use of force. Findings reveal significant variations in support based on the distance from the conflict zone, with Czech respondents less inclined to support intervention in Taiwan, contrasting with Japanese respondents. These insights pose critical considerations for the future of the liberal international order and military planning, underscoring the challenges in garnering widespread public backing for interventions in geographically distant scenarios.