A few thoughts:
I think you have to look at it from an institutional standpoint. If you interpret Hitler’s actions in the context of the institution he was involved in - the state - his actions violate the NAP; he utilized stolen materials, and utilized labor payed for by conterfieted and stolen money.
Now, one might observe that an individual using medicare or what have you is “utilizing stolen materials.” However, I think there is a difference in being a beneficiary of stolen goods (moreover, a significantly smaller sum of stolen goods), and being a beneficiary of stolen goods while being at the forefront (in terms of decision making especially) of the institution which steals the goods.
Now, interpreting Hitler’s actions as if he were a private individual is a bit more difficult. Assume there is a fictional group - one predicated on the idea that blacks are a sub-human species and need to be erradicated (why they don’t feel the need to erradicate other “sub-human species” is a mystery).
In one instance, say the group is peaceful. They boycott black stores; perhaps they completely disassociate themselves with blacks to the fullest extent. Being non-violent, no one, including the leader, is violating the NAP.
Now, assume they are a violent organization. They commonly lynch and commit other violent, heinous acts against blacks. Obviously the specific individuals commiting the acts are violating the NAP.
However, what about the leader (assuming he does nothing more than encite hatred, promote, and plan the use of violence). Is he not merely engaging in pursasion, and thus complying with the NAP? I say no. [Deleted stupid thoughts]
Revision: I say it depends.. Kinda..
The relevant question is, when does a threat begin. I think if someone marches around, promoting the use of violence against a particular group, this is on the edge of violating, but still is complying with the NAP; it is merely pursuasion absent a backing of force (compared to a threat i.e. pursuasion backed by force). However, as soon as one enters into an organization, insitution, or some form of arrangement that violates the NAP, he too is partaking in a violation of the NAP
EDIT:
Nevermind, the above is all wrong. The answer is actually pretty simple.
Someone here said that other autonomous individuals can not be used as means to an end. Of course they can. When I buy a piece of fruit from a fruit stand, I’m using the individual running it as a means to an end (the end being my hunger).
Now, when an individual hires a hitman or leads a violent hate-group, they are simply using other individuals as a means to an end. That does not take away the responsibility from the individual commiting the act (I hesitate to use the word “commiting,” because my point is that planning an act is part of commiting it). It also does not mean the invidivual “commiting” the act is soley the one responsible.
So in summary, if I were to do nothing but lead a rampage against a Jewish neighborhood, pillaging their property and what not, I would be violating the NAP, because an equally important part of the aggression is the planning (or leading; just some matter of involvment where I’m using others as a mean to an end) of the aggression. However, if I were just to cheer on the pillaging, I think I’d be innocent of agression.
EDIT:
Scratch that. That was stupid. If I cheer it on, I could still be using others as a mean to my end.. If my end were to have the Jews pillaged. But that doesn’t seem right. So basically, I have no idea how to draw a distinction between participating or not participating in an aggressive act.
Maybe merely joining a hate-group that commits acts of violence is akin to taking responsibility for the violence? But that seems more like collectivism than libertarianism.
But does anyone agree that hiring a hitman seems obviously to be engaing in the aggressive act.. As does creating an attack strategy on innocent civilians or something? But where is the line drawn?
Anyways, this is more a problem for NAP than a stateless society (it doesn’t seem like a problem at all for the latter).