Certain need to broadcast the French agreement (7,8)
I believe the answer is:
entente cordiale
'agreement' is the definition.
(entente cordiale is a kind of agreement)
'certain need to broadcast the french' is the wordplay.
'broadcast' indicates anagramming the letters.
'the french' becomes 'le'.
'certain'+'need'+'to'='certainneedto'
'certainneedto' is an anagram of 'ententecordia'.
'ententecordia'+'le'='ENTENTE CORDIALE'
(Other definitions for entente cordiale that I've seen before include "Agreement" , "Understanding" .)