It compulsorily takes its own charges, set by itself. So the Dominant Protection Agency becomes a state - it protects everyone, enforces a monopoly in the use of force, and raises taxes. The distinction between clients and non-clients drops out, and it no longer looks like a business enterprise. Note that there has been no argument that the state must be democratic. This can all be taken as an alternative to Locke's version of how civil society comes out of State of Nature.
Tacit consent is brought in to explain how everyone becomes a party to the agreement.
And without any violation of natural rights. So if we imagine, as Locke does, that people at first lived without government, in a state of nature, the question is whether government could come into existence without violating natural rights. Locke says it could and did, by consent - people voluntarily accepted a certain obligation to obey an umpire, the government. Nozick suggests that it may come about in another way. It seems to fit history better than Locke's account.