Libertarians who believe that the government can be used to protect freedom and who believe in the current regime of private property as it has evolved under the state, are indeed caught in a sort of set of contradictions. Where does the money come from to pay the police officer or soldier? How did the current legal boundaries of what is property come to exist?
Speaking of which, I've been lax in self-promotion of my own C4SS columns. My most recent piece is about former World Wrestling Entertainment CEO Linda McMahon's campaign for US Senate. Check it out. Maybe you'll like it.