buffer country vs buffer state

buffer country and buffer state both are nouns.

Word	Noun	Adjective	Verb	Adverb
buffer country	Yes	No	No	No
buffer state	Yes	No	No	No

As nouns, buffer country and buffer state are synonyms defined as:

buffer country and buffer state: a small neutral state between two rival powers

buffer country (noun)	buffer state (noun)
a small neutral state between two rival powers	a small neutral state between two rival powers