Is one surrounded by fish in this country? (7)
I believe the answer is:
tunisia
'in this country?' is the definition.
(I've seen this before)
'is one surrounded by fish' is the wordplay.
'one' becomes 'i' (Roman numeral).
'surrounded by' means one lot of letters goes inside another.
'fish' becomes 'tuna' (tuna is a type of fish).
'is'+'i'='isi'
'isi' put into 'tuna' is 'TUNISIA'.
(Other definitions for tunisia that I've seen before include "African republic on the Mediterranean coast" , "African state" , "Country where Carthage is found" , "Country which contains the site of Carthage" , "Suit Ian to be in North African country" .)