The state is a necessary evil, most useful and beneficial when it protects citizens from the predations of libertarians, communists, and other anarchists.
I would not lump in libertarians and communists. The two are polar opposites. And libertarians did not lead to the death of tens of millions of people last century. Pinkos did. A libertarian would never sanction the gulag.
The state is like any other human tool. When the state is used to first create rules for human contracts and then enforce them fairly, you get the most free society. When the state is used to force people towards equality, you end up with more repression. That is the irony of the nanny state.
Hong Kong had a pretty libertarian approach to government and it prospered as a result. The flip side is, the people of that state were of a disciplined and productive mindset. So libertarianism, IMO, is only truly effective in a population that is not prone to the libertine. It, like many other belief systems, has its points. But it cannot function effectively by itself (like many belief systems) - it needs to be coupled to something else (like Confucian discipline in the example of Hong Kong) to work in the real world.
The most dangerous people, after all, are those who refuse to let reality interact with their belief systems, such as Marxist liberals and Islamists.