Talk about Peace Force (5)
I believe the answer is:
wrest
'force' is the definition.
(thesaurus)
'talk about peace' is the wordplay.
'talk about' indicates a 'sounds like' (homophone) clue (I've seen 'talked about' mean this).
'peace' becomes 'rest' (I've seen this in other clues).
'rest' is a homophone of 'WREST'.
(Other definitions for wrest that I've seen before include "Take away forcibly" , "The old piano tuner" , "Obtain forcibly" , "Remove with force" , "Snatch from" .)