What may follow invasion craft (10)
I believe the answer is:
occupation
I believe this clue is a double definition.
'what may follow invasion' is the first definition.
(invading forces may occupy a territory)
'craft' is the second definition.
(both can mean someone's profession or trade)
(Other definitions for occupation that I've seen before include "Calling" , "the seizure and control of a foreign territory" , "end of invasion?" , "Doctor, for instance" , "period of residency" .)