Offensive occupation? (8)
I believe the answer is:
invasion
I believe this is a double definition.
'offensive' is the first definition.
(thesaurus)
'occupation?' is the second definition.
(I've seen this before)
(Other definitions for invasion that I've seen before include "Unwelcome intrusion" , "Incursive attack" , "Encroachment by an army" , "Entry into foreign country to conquer it" , "Encroachment by enemy" .)