peacekeeping operation vs war machine

peacekeeping operation and war machine both are nouns.

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

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