Attack right back stops posing no threat (6)
I believe the answer is:
strafe
'attack' is the definition.
(to strafe is to attack from the air)
'right back stops posing no threat' is the wordplay.
'right' becomes 'rt' (abbreviation as in Rt Hon- the Right Honourable).
'back' says the letters should be written in reverse.
'stops' indicates putting letters inside.
'posing no threat' becomes 'safe' (not threatening or dangerous).
'rt' back-to-front is 'tr'.
'tr' put into 'safe' is 'STRAFE'.
(Other definitions for strafe that I've seen before include "Spray with bullets" , "attack with flying arms" , "Attack from the air with machine guns" , "Pepper" , "Bombard" .)