Secure area to the north in Asian country (5)
I believe the answer is:
chain
'secure' is the definition.
(chaining is a kind of securing)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for chain that I've seen before include "Length of pitch" , "distance for a run?" , "a number of hotels" , "Series of links; sixty six feet" , "trading group" .)