military vs theatre of operations

military and theatre of operations both are nouns.

Word	Noun	Adjective	Verb	Adverb
military	Yes	Yes	No	No
theatre of operations	Yes	No	No	No

military (noun)	theatre of operations (noun)
the military forces of a nation	a region in which active military operations are in progress

military (adjective)	theatre of operations (adjective)
associated with or performed by members of the armed services as contrasted with civilians
characteristic of or associated with soldiers or the military
of or relating to the study of the principles of warfare