Country I left, claimed by revolutionary (5)
I believe the answer is:
chile
'country' is the definition.
(Chile is a country)
'i left claimed by revolutionary' is the wordplay.
'left' becomes 'l' (common abbreviation).
'claimed by' means one lot of letters goes inside another.
'revolutionary' becomes 'Che' (Che Guevara).
'i'+'l'='il'
'il' put into 'che' is 'CHILE'.
(Other definitions for chile that I've seen before include "Long narrow country" , "Long, thin country" , "S American country, capital Santiago 95)" , "Country of S. America" , "South American country" .)