Any Rothbardian anarcho-capitalist has no doubt been confronted with the assertion that a state is necessary to enforce the property rights so vital to a market-based, capitalist system. 

Is this true?

Defining the State 

Before proceeding any further, its imperative to establish what we mean when describing "the state."

In a brilliant 1974 lecture entitled "Society Without a State," presented online here, Murray Rothbard laid out a concise definition:

"Let me say from the beginning that I define the state as that institution which possesses one or both (almost always both) of the following properties: (1) it acquires its income by the physical coercion known as "taxation"; and (2) it asserts and usually obtains a coerced monopoly of the provision of defense service (police and courts) over a given territorial area."