Dissident sure to go crazy with knife (9)
I believe the answer is:
refusenik
'dissident' is the definition.
(refusenik can mean someone opposing the government)
'sure to go crazy with knife' is the wordplay.
'to go crazy with' indicates anagramming the letters (a crazy ordering of the letters).
'sure' anagrammed with 'knife' makes 'REFUSENIK'.
(Other definitions for refusenik that I've seen before include "Protester" , "who refuses to cooperate" , "Soviet dissident" .)