Pretty sure if all the parties at the Peace Talks agreed to an Arbiter and then one of the parties crossed that arbiter, every other party would come down on them like a load of bricks. Now that I write that, I kind of want to see it.
Reminds me of the scene in the Eragon series where the Dwarf council punishes one of its members by ignoring him completely no matter what he does. Seeing that dwarf try to get everyones attention and growing more and more frustrated/frantic was extremely gratifying.