Soldiers in a salute showing assent (9)
I believe the answer is:
agreement
'assent' is the definition.
(thesaurus)
'soldiers in a salute' is the wordplay.
'soldiers' becomes 'men' (I've seen this before).
'in' means one lot of letters goes inside another.
'salute' becomes 'greet' (I've seen this before).
'a'+'greet'='agreet'
'men' inserted inside 'agreet' is 'AGREEMENT'.
'showing' is the link.
(Other definitions for agreement that I've seen before include "Harmony of opinion" , "in sympathy" , "Compact, accord" , "Conformity" , "State of being consistent" .)