Rogue operation in effect (6)
I believe the answer is:
impact
'effect' is the definition.
(I know that impact is a type of effect)
'rogue operation' is the wordplay.
'rogue' becomes 'imp'.
'operation' becomes 'act'.
'imp'+'act'='IMPACT'
'in' acts as a link.
(Other definitions for impact that I've seen before include "The striking of one thing against another" , "The force of one body against another" , "Forceful striking" , "Marked effect or influence" , "Repercussion" .)