A hard villain brought about Russian retreat (5)
I believe the answer is:
'russian retreat' is the definition.
(I've seen this before)
'a hard villain brought about' is the wordplay.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'villain' becomes 'cad' (cad can mean a nasty person).
'brought about' is a reversal indicator.
'ahcad' in reverse letter order is 'DACHA'.
(Other definitions for dacha that I've seen before include "property overseas" , "Russian holiday cottage" , "Second home in the country for Muscovites?" , "Russian's second home in the country" , "A Russian country cottage" .)