Make good progress at first, protected by soldiers' aura (6)
I believe the answer is:
repair
'make good' is the definition.
(thesaurus)
'progress at first protected by soldiers' aura' is the wordplay.
'at first' suggests taking the first letters.
'protected by' indicates putting letters inside.
'soldiers'' becomes 're' (I've seen this in other clues).
'aura' becomes 'air' ('air' can be a synonym of 'aura').
The first letter of 'progress' is 'p'.
're'+'air'='reair'
'p' going inside 'reair' is 'REPAIR'.
(Other definitions for repair that I've seen before include "Mend - go" , "Restore to working condition" , "retire" , "Travel or proceed toward some place" , "Mend, put right" .)