Soviet Russia vs Russian

Soviet Russia and Russian both are nouns.

Word	Noun	Adjective	Verb	Adverb
Soviet Russia	Yes	No	No	No
Russian	Yes	Yes	No	No

Soviet Russia (noun)	Russian (noun)
formerly the largest Soviet Socialist Republic in the USSR occupying eastern Europe and northern Asia	the Slavic language that is the official language of Russia
	a native or inhabitant of Russia

Soviet Russia (adjective)	Russian (adjective)
	of or pertaining to or characteristic of Russia or its people or culture or language