The recent literature on China's relations with North Vietnam has given insufficient attention to the impact of the Sino-Soviet conflict. This article underscores the centrality of the Soviet factor in Beijing's relations with Hanoi and the importance of triangular relations during the 1964–1968 period. The article points to the Sino-Soviet conflict as the main cause of the fissures in the Sino-North Vietnamese alliance that emerged more fully after the Vietnam War.