Turns up in agreement with Arab leader (5)
I believe the answer is:
emeer
'arab leader' is the definition.
(historical title in Islamic countries)
'turns up in agreement' is the wordplay.
'turns up' is a reversal indicator.
'in' indicates a hidden word.
'reeme' is hidden within 'agreement'.
'reeme' back-to-front is 'EMEER'.
'with' is the link.
(Other definitions for emeer that I've seen before include "Islamic governor" , "Leader of Arabs" , "Islamic title" , "independent ruler" , "Prince" .)