A state monopoly on violence emerged at (almost) all locations that had a prior Neolithic revolution (the rise of agriculture). This suggests some kind of regularity. We use the security dilemma game to show that the fear of violence leads to wasteful arms races and conflict. A state monopoly on violence contains this threat, albeit at the cost of kleptocracy by a small dominant coalition holding this monopoly on violence. However, this monopoly can only be used effectively if the dominant coalition is able to commit to not abusing its capacity for violence. Using the framework of an infinitely repeated prisoners’ dilemma, the chapter identifies necessary conditions for cooperation.