Song put soldier on edge (6)
I believe the answer is:
anthem
'song' is the definition.
(anthem is a kind of song)
'soldier on edge' is the wordplay.
'soldier' becomes 'ant' (I've seen this before).
'on' is a charade indicator (letters next to each other).
'edge' becomes 'hem' (I've seen this before**).
'ant'+'hem'='ANTHEM'
'put' is the link.
(Other definitions for anthem that I've seen before include "air of patriotism?" , "The man for a popular song" , "National or church song" , "Uplifting song -- the man (anag)" , "Internationale?" .)