Attack SAS, Goering ordered (10)
I believe the answer is:
aggression
'attack' is the definition.
(I have seen 'Unprovoked attack' mean 'aggression' so perhaps 'attack' could also mean 'aggression')
'sas goering ordered' is the wordplay.
'ordered' is an anagram indicator.
'sas'+'goering'='sasgoering'
'sasgoering' with letters rearranged gives 'AGGRESSION'.
(Other definitions for aggression that I've seen before include "What eleven Ac displays" , "Use of armed force" , "Act of aggression,physical force" , "Belligerence -hostility" , "Unprovoked attack" .)