"However, this monopoly is limited to a certain geographical area, and in fact this limitation to a particular area is one of the things that defines a state."

"However, this monopoly is limited to a certain geographical area, and in fact this limitation to a particular area is one of the things that defines a state." International relations is a manifestation of multiple monopolies on violence in different geographic areas interacting. They either find some sort of equilibrium for a period of time or they war and new boundaries are defined. The law of physics statement was hyperbole, but my point is anarchy doesn't last, it is quickly replaced with a monopoly of violence, because it has to be.