A common libertarian understanding of the debate between minarchists and anarchists is to view it as a sliding scale. E.g. minarchism is far less State aggression and anarchism is none. There are lots of caveats, such as some minarchists think there can be a State without aggression, or that anarchism will actually have more aggression. But let’s leave those aside for now.
This common understanding suggests minarchists and anarchists are on the same path, or even that the minarchists and anarchists debate is pointless until we reach minarchy. I think this is incorrect.
Minarchism is a centralist political philosophy. It maintains that rights should be determined as well as enforced by a central authority. In a sense, this is a small, limited State if it is confined to these functions. However, in another sense, it is not very limited at all.
The problem is, despite what many libertarians think, there is not 1 single interpretation of property rights that is objectively correct. Even if we are speaking of only libertarians who uphold the NAP as their guiding principle, there is vast disagreement as to what constitutes aggression.
Some examples: at what height over a person’s house does flying a drone become aggressive? Is copyright legitimate? At exactly what speed does driving through a school zone become reckless endangerment? What riparian water rights do we have? Is it aggressive to stop someone from attempting suicide? When does a child reach legal adulthood? Where is the line separating asymmetrical information and fraud? Are easement rights legitimate? What level of violence is justified in defense of a burglary? Ask these or many others to a group of seemingly similar libertarians, and you will likely get a variety of answers. This doesn’t even scratch the surface of related ideologies, such as Mutualism, or Geo-libertarianism.
Minarchism, by definition, must pick an answer to all these disagreements and force it upon everyone. Given there will be many honest disagreements even among libertarians, the resources devoted to enforcing the State’s choice will be significant. What at first appeared to be a small State, is actually a central authority that must wield immense power. The question of what our rights are underlies every interaction we have. A State that is limited to delineating and enforcing rights, is still involved and oversees every part of our lives.
Conversely, the anarchist envisions a world where property rights are created through bottom-up mechanisms. Even within a community, rights could vary depending on who you are interacting with. The anarchist recognizes various peoples will find different answers to the above questions which are better suited for their particular situation.
Here then is the crux. The minarchist desires their particular interpretation of aggression to be outlawed, while the anarchist wants to allow for different interpretations of aggression. No doubt, there are many things the 2 can agree on and work together toward (by no means do I oppose coalition), but while most minarchists will support the allocation of resources toward the justice system in order to uphold property rights, I think anarchists should not. I would go so far as to say an anarchist should work to undermine and work around law enforcement, as that will lessen the impact of any legislation that is passed. With a weak enforcement arm, oppressive legislation makes little difference. For the minarchist, the weakening of law enforcement in general, means they are moving away from a State that enforces property rights.
The difference between minarchists and anarchists is not minor or irrelevant. They are competing political philosophies in important ways. Do not, however, allow this to persuade you to abandon coalitions that are of mutual benefit.