After the Kuomintang (KMT) lost control of mainland China in 1949, some of its troops retreated to mainland Southeast Asia, marking the start of a period of mutual interaction between the KMT troops and Southeast Asian states in the context of the Cold War. The objective of this paper is to focus on the KMT troops who retreated to Northern Thailand. The author argues that the KMT troops, as protagonists in border areas, promoted border consolidation in Northern Thailand through war and village building. The Thai government, lacking effective jurisdiction over the border, took advantage of the KMT, using it as the most effective tool for border management and as a military force to counter the Communist threat along border areas. Through years of fighting with the Communist Party of Thailand (CPT), KMT troops helped eliminate potential security risks in Northern Thailand. Consequently, border villages with defenses bolstered during the war years epitomized the Northern Thai border being brought under the aegis of state control.