war of nerves vs warfare

war of nerves and warfare both are nouns.

Word	Noun	Adjective	Verb	Adverb
war of nerves	Yes	No	No	No
warfare	Yes	No	No	No

As nouns, warfare is a hypernym of war of nerves; that is, warfare is a word with a broader meaning than war of nerves:

war of nerves: the use of psychological tactics to destroy the opponents' morale
warfare: the waging of armed conflict against an enemy

Other hypernyms of war of nerves include war.

war of nerves (noun)	warfare (noun)
the use of psychological tactics to destroy the opponents' morale	the waging of armed conflict against an enemy
	an active struggle between competing entities