war machine vs peacekeeping operation

war machine and peacekeeping operation both are nouns.

Word	Noun	Adjective	Verb	Adverb
war machine	Yes	No	No	No
peacekeeping operation	Yes	No	No	No

war machine (noun)	peacekeeping operation (noun)
the military forces of a nation	the activity of keeping the peace by military forces (especially when international military forces enforce a truce between hostile groups or nations)