Join revolution before the French (6)
I believe the answer is:
couple
'join' is the definition.
(coupling is a kind of joining)
'revolution before the french' is the wordplay.
'revolution' becomes 'coup' (a coup against the state).
'before' says to put letters next to each other.
'the french' becomes 'le' ('the' in French).
'coup'+'le'='COUPLE'
(Other definitions for couple that I've seen before include "Pair - put together" , "Bonnie and Clyde, say" , "Duo, brace" , "Twosome" , "Two - join up" .)