Occupied region – wrong one (6)
I believe the answer is:
crimea
'occupied region' is the definition.
The answer and definition can be both locations as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'wrong one' is the wordplay.
'wrong' becomes 'crime' (I've seen this before).
'one' becomes 'a' (a thing is one thing).
'crime'+'a'='CRIMEA'
Can you help me to learn more?
(Other definitions for crimea that I've seen before include "'Ukrainian peninsula, site of a 19th-century war (6)'" , "Ukrainian peninsula, theatre of 1853-6 war" , "old war zone" , "Ukrainian peninsula, scene of war" , "Ukraine peninsula, scene of war (1853-6)" .)