Nothing's achieved by being dominated by foreign dissent (9)
I believe the answer is:
nonentity
'nothing's' is the definition.
(thesaurus)
'by being dominated by foreign dissent' is the wordplay.
'by' is a charade indicator (letters next to each other).
'being' becomes 'entity' (I've seen this in other clues).
'dominated by foreign dissent' becomes 'non' (I can't explain this - if you can you should give a lot more credence to this answer).
'entity' after 'non' is 'NONENTITY'.
'achieved' is the link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for nonentity that I've seen before include "Person of no influence" , "Unimportant person" , "Person of no importance" , "Insignificant person" , "A nobody" .)