class war vs class warfare

class war and class warfare both are nouns.

Word	Noun	Adjective	Verb	Adverb
class war	Yes	No	No	No
class warfare	Yes	No	No	No

As nouns, class war and class warfare are synonyms defined as:

class war and class warfare: conflict between social or economic classes (especially between the capitalist and proletariat classes)

Other synonyms of class war include class struggle.

class war (noun)	class warfare (noun)
conflict between social or economic classes (especially between the capitalist and proletariat classes)	conflict between social or economic classes (especially between the capitalist and proletariat classes)