Ruler from East on edge after revolution (4)
I believe the answer is:
emir
'ruler' is the definition.
(emir is a kind of ruler)
'east on edge after revolution' is the wordplay.
'east' becomes 'e' ('E' can be a synonym of 'east').
'on' means one lot of letters go next to another.
'edge' becomes 'rim' (rim is a kind of edge).
'after revolution' shows that the letters should be reversed in order.
'rim' back-to-front is 'mir'.
'e'+'mir'='EMIR'
'from' is the link.
(Other definitions for emir that I've seen before include "Middle-Eastern ruler" , "Middle Eastern ruler" , "Arab ruler" , "Eastern ruler in mire" , "eader abroad?" .)