military machine vs armed forces

military machine and armed forces both are nouns.

Word	Noun	Adjective	Verb	Adverb
military machine	Yes	No	No	No
armed forces	Yes	No	No	No

As nouns, military machine and armed forces are synonyms defined as:

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

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