The Soviet Union was invaded.
 In the east, the Soviet military won several decisive victories during border clashes with the Empire of Japan in 1938 and 1939
 The beginning of the Cold War saw the Eastern Bloc of the Soviet Union confront the Western Bloc of the United States, with the latter grouping becoming largely united in 1949 under NATO and the former grouping becoming largely united in 1955 under the Warsaw Pact

