Always protected by right to go back (6)
I believe the answer is:
revert
'go back' is the definition.
(to revert is to go back or regress)
'always protected by right' is the wordplay.
'always' becomes 'ever' (synonyms).
'protected by' indicates putting letters inside.
'right' becomes 'rt' (abbreviation as in Rt Hon- the Right Honourable).
'ever' put inside 'rt' is 'REVERT'.
'to' is the link.
(Other definitions for revert that I've seen before include "Go back to a previous state" , "Return to former condition or habit" , "Return to (earlier state)" , "Go back to type" , "Go back (to topic)" .)