This article examines the North Korean city of Sinǔiju during the era of Soviet occupation, focusing specifically on the Sinǔiju incident of 23 November 1945. A violent clash between local youth and Communist security forces, the incident revealed the combustible mixture of factors present in postcolonial North Korea. The Soviet military government’s deadly response to the protests seriously threatened Korea’s receptiveness to the Korean Communist Party and to the Soviet Union, and forced stronger control over both the city of Sinǔiju and youth nationwide. This article considers the visit that Kim Il Sung (Kim Ilsŏng) made to Sinǔiju in the aftermath of the incident, as well as subsequent North Korean policies in Sinǔiju. Drawing on previously untapped files from the Archive of Military History of the Russian Federation, newly declassified CIA documents, and Korean- and Chinese-language texts, this article examines a North Korean city whose peripheral influence in the postcolonial period has not yet been adequately understood.