With the encouragement of the Soviet Union, Manchuria was then used as a staging ground during the Chinese Civil War for the Communist Party of China, which emerged victorious in 1949. Ambiguities in the treaties that ceded Outer Manchuria to Russia led to dispute over the political status of several islands. As part of the Sino-Soviet split, this ambiguity led to armed conflict in 1969, called the Sino-Soviet border conflict, resulting in an agreement.