In any human polity - libertarian or otherwise - there will always be rules of some kind, and so also of course the application of those rules.
[1]
Thus, there will always be
appliers of those rules (i.e., "rulers") - whether they be called "princes" or "presidents" or "CEOs of private security firms" or what-have-you. Even under a voluntaryist polity, there will necessarily be systems and networks of collectively cooperative deference that will result in a hierarchy of such "rulers"
[2]. (That they may not be explicitly identified or thought of as "rulers" is a matter of semantics and narrative framing.)
Can't argue the fact, just simply stating that it's a pipe dream until the day comes when every single person accepts and lives by the NAP.
I hope that day comes sometime.
Sadly, that day will never come.
At an absolute minimum, there will always be at least some number of sociopathic types who have no compunctions when it comes to violating the rules (whatever the rules might be, including the NAP). And even beyond those, there will always be non-sociopaths who will nevertheless support (or at least not oppose) aggression - because [reasons (e.g., "it's for the children")].
Fortunately, the achievement and maintenance of a libertarian polity does not require that "every single person accepts and lives by the NAP". Indeed, it does not even require that a majority does so - or even a plurality. for that matter. It only requires that
enough people do so (however much that might be
[3]). More specifically, it requires that enough of the right people in the right positions - enough of the aforementioned "appliers of rules", in other words - do so. Under those circumstances, the question of whether Joe Rando is a believer in the NAP or not becomes irrelevant, or at most secondary.
[1] In fact, it is the nature and substance of those rules which determine whether (and to what extent) a given polity can be deemed to be "libertarian or otherwise" in the first place.
[2] To invoke an analogy used earlier in this thread, even in a voluntaryist game of "pick up" baseball, the umpire (i.e., "ruler") must necessarily be deferred to by all the players if the game is to occur or continue - even when (or rather,
especially when) some of them think his strike zone is too big or too small.
[3] Ante facto, there is no way of knowing what this quantity is, and it will surely vary widely according to time, place, and other contingent factors.
