Fool is beginning to taunt soldier and aide (9)
I believe the answer is:
assistant
'aide' is the definition.
(thesaurus)
'fool is beginning to taunt soldier' is the wordplay.
'fool' becomes 'ass' (ass is a kind of fool**).
'beginning to' indicates taking the first letters.
'soldier' becomes 'ant' (I've seen this before).
The initial letter of 'taunt' is 't'.
'ass'+'is'+'t'+'ant'='ASSISTANT'
'and' is the link.
(Other definitions for assistant that I've seen before include "Deputy, subordinate" , "one helps out" , "One helping" , "Attendant, helper" , "Aide, helper" .)