There are currently 192 governments, which is no indicative of a monopolistic market.
You are wrong, they have a monopoly of violence
over a specific territory. They generally agree who has the monopoly where. If there are some disagreements between them, there is a tension that eventually ends up with a violent war. And then they fight each other over the turf like common street gangs do. The only difference is that a lot less civillians die in gang wars.
I wish I could hold so tightly to such a simplistic view of international politics. Exaggeration and unbridled hate is certainly easier that nuance and understanding.