Pointer to dispute undermining Arabia (5)
I believe the answer is:
arrow
'pointer' is the definition.
(synonyms)
'dispute undermining arabia' is the wordplay.
'dispute' becomes 'row' (row is a kind of dispute).
'undermining' says to put letters next to each other.
'arabia' becomes 'Ar.' (abbreviation in Chambers).
'row' after 'ar' is 'ARROW'.
'to' acts as a link.
(Other definitions for arrow that I've seen before include "Early guided missile" , "It may indicate" , "pointer to the way forward" , "Pointed weapon" , "Weapon from bow" .)