Original: Vendetta is typical of societies with a weak rule of law (or where the state does n't consider itself responsible for mediating this kind of dispute) where family and kinship ties are the main source of authority.
Simplified: Vendetta is typical of societies with a weak rule of law or in those where the state does not consider itself responsible for helping with this kind of dispute. In such societies, family and kinship ties are the main source of authority.