It's a crime to break peaceful agreement (9)
I believe the answer is:
armistice
'peaceful agreement' is the definition.
The definition and answer can be both states of affairs as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'it's a crime to break' is the wordplay.
'to break' indicates an anagram.
'its'+'a'+'crime'='itsacrime'
'itsacrime' anagrammed gives 'ARMISTICE'.
Can you help me to learn more?
(Other definitions for armistice that I've seen before include "Agreement during war to suspend fighting" , "Fire is prevented by this" , "when shooting stops" , "harbinger of peace?" , "Truce" .)