In favour of western front (4)
I believe the answer is:
prow
'front' is the definition.
(prow is a kind of front)
'in favour of western' is the wordplay.
'in favour of' becomes 'pro' (I've seen this before).
'western' becomes 'w'.
'pro'+'w'='PROW'
(Other definitions for prow that I've seen before include "position of figurehead" , "Bow of a ship" , "Bow of a vessel" , "Pointed front part of a ship" , "Boat's bow" .)