A service on border in Dutch city (6)
I believe the answer is:
arnhem
'dutch city' is the definition.
(I've seen this before)
'a service on border' is the wordplay.
'service' becomes 'rn' (abbreviation for Royal Navy).
'on' is a charade indicator (letters next to each other).
'border' becomes 'hem' (I've seen this before).
'a'+'rn'+'hem'='ARNHEM'
'in' is the link.
(Other definitions for arnhem that I've seen before include "Dutch city" , "Second World War battle" , "place noted for fighting" , "WW2 battle" , "Site of 1944 battle" .)