Country song about American troop leader (7)
I believe the answer is:
austria
'country' is the definition.
(I know that Austria is a European country)
'song about american troop leader' is the wordplay.
'song' becomes 'aria' (piece of music in an opera).
'about' indicates putting letters inside.
'american' becomes 'US' (United States).
'leader' says to take the initial letters.
The initial letter of 'troop' is 't'.
'us'+'t'='ust'
'aria' placed around 'ust' is 'AUSTRIA'.
(Other definitions for austria that I've seen before include "Its aura is in Europe" , "Central European republic" , "US tiara to be found in this country, oddly" , "land in Europe" , "One state" .)