Mises actually nailed it:
We may agree that he who acts antisocially should be considered mentally sick and in need of care. But as long as not all are cured, and as long as there are infants and the senile, some provision must be taken lest they jeopardize society. An anarchistic society would be exposed to the mercy of every individual. Society cannot exist if the majority is not ready to hinder, by the application or threat of violent action, minorities from destroying the social order. This power is vested in the state or government.
He just failed to connect this to the natural law in a “small society,” as outlined in previous posts.
Even that is not entirely true; witness:
Every step by which an individual substitutes concerted action for isolated action results in an immediate and recognizable improvement in his conditions. The advantages derived from peaceful cooperation and division of labor are universal. They immediately benefit every generation, and not only later descendants. For what the individual must sacrifice for the sake of society he is amply compensated by greater advantages. His sacrifice is only apparent and temporary; he foregoes a smaller gain in order to reap a greater one later. No reasonable being can fail to see this obvious fact.
No reasonable being indeed, but only in a small society, not a large one; hence the reason for the state in a large society!