Descriptively history, normatively society through whatever mechanisms it comes up with. (Eg. in the US it's done through an "by default everything is allowed, and SCOTUS can make exceptions" mechanism.)

I don't think there's anything wrong with advocating for peace, from a free speech aspect, especially if someone is sincere. (Even if someone is completely brainwashed by whatever propaganda. And even if peace itself is a super meaningless term. After all wouldn't a totalitarian world government bring peace? Etc, etc.)