war machine vs military machine

war machine and military machine both are nouns.

Word	Noun	Adjective	Verb	Adverb
war machine	Yes	No	No	No
military machine	Yes	No	No	No

As nouns, war machine and military machine are synonyms defined as:

Other synonyms of war machine include armed forces, armed services, military.

war machine (noun)	military machine (noun)
the military forces of a nation	the military forces of a nation