armed forces vs war zone

armed forces and war zone both are nouns.

Word	Noun	Adjective	Verb	Adverb
armed forces	Yes	No	No	No
war zone	Yes	No	No	No

armed forces (noun)	war zone (noun)
the military forces of a nation	a combat zone where military operations are coordinated (especially a designated area in international waters where the rights of neutrals are not respected by nations at war)