Changing tone, Iran elected for alliance (7,8)
I believe the answer is:
entente cordiale
'alliance' is the definition.
(entente cordiale is a kind of alliance)
'changing tone iran elected' is the wordplay.
'changing' indicates anagramming the letters.
'tone'+'iran'+'elected'='toneiranelected'
'toneiranelected' with letters rearranged gives 'ENTENTE CORDIALE'.
'for' is the link.
(Other definitions for entente cordiale that I've seen before include "Understanding" , "Agreement" .)