Good French soldier returning to the French base (7)
I believe the answer is:
ignoble
'base' is the definition.
('ignoble' can be similar in meaning to 'base')
'good french soldier returning to the french' is the wordplay.
'good french' becomes 'bon'.
'soldier' becomes 'gi' (government issue or general issue).
'returning' shows that the letters should be reversed in order.
'to the french' becomes 'le'.
'bon'+'gi'='bongi'
'bongi' written backwards gives 'ignob'.
'ignob'+'le'='IGNOBLE'
(Other definitions for ignoble that I've seen before include "Not honourable in character or purpose" , "I belong (anag)" , "Base, not honourable" , "'Dishonourable, mean (7)'" , "Lacking dignity" .)