Island preserve a spy agency subverted (7)
I believe the answer is:
jamaica
'island' is the definition.
(island nation)
'preserve a spy agency subverted' is the wordplay.
I cannot quite understand how this works, but
'preserve' could be 'jam' (jam is a kind of preserve) and 'jam' is found within the answer.
'a' is within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for jamaica that I've seen before include "Island in the West Indies" , "Caribbean island state" , "West Indian island" , "location of Live and Let Die" .)