Question: What is the military power's name formed by the new government of the soviet Union and fought in the the Soviet-Japanese border conflicts among the Soviet Union, mongolia, japan and Manchukuo  in 1939?
Sentence (from "Military history of the Soviet Union"): The Red Army invaded Finland (November 1939); fought the Battles of Khalkhin Gol of May-September 1939 (together with its ally Mongolia) against Japan and its client state Manchukuo; it was deployed when the Soviet Union, in agreement with Nazi Germany, took part in the invasion of Poland in September 1939, and occupied the Baltic States (June 1940), Bessarabia (June–July 1940) and Northern Bukovina (June–July 1940) (from Romania).
Relevant evidence: No