What political system did Robert Nozick defend in Anarchy, State, and Utopia?

In his 1974 work Anarchy, State, and Utopia, American philosopher Robert Nozick defended the minimal state.12

Nozick characterized this system as a "night watchman" state, possessing only the powers necessary to protect citizens against violence, theft, and fraud. He argued that this is the only form of government that is morally justified, as any state with more extensive powers—such as those that regulate economic activity, redistribute wealth, or provide social services—would violate the natural rights of its citizens.1

His defense of the minimal state is rooted in his entitlement theory of justice, which posits that a distribution of holdings is just if it arises from legitimate means, such as voluntary transfer or original acquisition. Nozick contended that attempts to enforce patterned distributions of wealth, such as those proposed by socialist or modern liberal ideologies, would require unjust, coercive interference in the lives of individuals. By protecting individual rights while allowing people the freedom to form smaller, voluntary communities, Nozick argued that the minimal state serves as a "framework for utopia".31