Failure of French action (6)
I believe the answer is:
defeat
'failure' is the definition.
(I've seen this before)
'of french action' is the wordplay.
'of french' becomes 'de'.
'action' becomes 'feat' (feat is a kind of action**).
'de'+'feat'='DEFEAT'
(Other definitions for defeat that I've seen before include "Overthrow" , "Conquest" , "Beat (an opponent)" , "Get the better of" , "Vanquish, win against" .)