Warns of newspapers penning article on the borders of Greece (8)
I believe the answer is:
presages
'warns' is the definition.
'newspapers penning article on the borders of greece' is the wordplay.
'newspapers' becomes 'press' (I've seen this before).
'penning' is an insertion indicator.
'article' becomes 'a' (indefinite article).
'on' says to put letters next to each other.
'the borders of' means to remove the middle letters.
'greece' with its middle taken out is 'ge'.
'a'+'ge'='age'
'press' enclosing 'age' is 'PRESAGES'.
'of' is the link.
(Other definitions for presages that I've seen before include "Forecasts" , "Augurs, bodes" , "Foreshadows in press age" , "Foreshadows, is advance sign of" .)