This article examines how the Korean War (1950–1953) fundamentally shaped South Korean society through three interconnected dimensions that persist today. First, the war facilitated the global construction and diffusion of anti-communist ideology, with Korean experiences used as propaganda tools worldwide, including the development of ‘brainwashing’ theories. Second, post-war reconstruction was driven by military imperatives with US aid primarily focused on maintaining strong Korean military divisions, establishing a war-oriented economic foundation that contributed to the chaebol system. Third, the militarization of society led to the systematic exclusion and stigmatization of vulnerable groups – war widows, orphans, disabled veterans and prisoners of war – who, despite being war victims, faced social discrimination and inadequate support. We argue that the war frames created by the Korean conflict have continued to influence South Korean society through military conscription systems and institutionalized anti-communism even after democratization. This article thus contributes to the sociology of the war–society nexus by highlighting the lasting and extensive effects of war in shaping social behaviours and beliefs.