Russia

The Soviet Union did not collapse in the 20th century in the Fallout world and still existed in the 21st century, prior to Great War. The Soviet Union had consular service and very likely foreign service, including consular relations with USA. Very likely wasn't at war with it in 2077. It is unknown whether during the Great War the Soviet Union was an ally of China, its enemy, or was neutral towards it, and it is unknown whether it still had its sphere of influence in Europe.

Soviet Union is not mentioned at all in other parts of the background, especially in background concerning the Great War. The name of the state still confirmed its continuity, so it still likely had a kind of communist system of government in the 21st century.