Go-between to admire when resolution has been established (8)
I believe the answer is:
mediator
'go-between' is the definition.
(synonyms)
'to admire when resolution has been established' is the wordplay.
'when resolution has been established' indicates anagramming the letters (when the anagram is resolved).
'to'+'admire'='toadmire'
'toadmire' is an anagram of 'MEDIATOR'.
(Other definitions for mediator that I've seen before include "One seeking to reconcile opponents" , "Kind of arbitrator - one to admire" , "One intervening to settle a dispute" , "Negotiator between opposing parties" , "An honest broker" .)