When did Robert Nozick believe people could punish violations of natural rights?

In the context of his political philosophy, Robert Nozick argued that in a hypothetical state of nature, every individual possesses the natural rights to life, liberty, and property.1

According to Nozick, individuals have the right to punish those who violate or attempt to violate their own natural rights. Because exercising this right to punishment and defense can be difficult for individuals to manage on their own, Nozick theorized that people would naturally form "protection associations" to collectively defend their rights and punish violators. These associations eventually evolve into the minimal state, which holds a monopoly on the legitimate use of force within a territory to protect the rights of its citizens.1