Also, it is possible for someone to be a libertarian at least nominally and not be an anarchist. So there are both libertarian anarchists and libertarians who are not anarchists, which generally describes the classic anarchist vs. minarchist split. The existance of libertarians who are not anarchists is a consequence of either too narrow or an interpretation of the principles or the superimposition of principles that create tension with libertarianism. Non-anarchist libertarians do not see the existance of a state or any fundamentals of a state as violating the libertarian principles, or they do see that but pragmatically endorse a minimal state anyways.
Then there are some libertarians who label themselves as anarchists but functionally take a minarchist position, or even a rabidly authoritarian position. This is often a consequence of bundling libertarianism with values that create tension, and the alien values win out. It probably is a great disservice to libertarianism to even grace such people with the term libertarian, but it is part of the baggage of the modern libertarian movement. At least some of the anarcho-capitalists functionally take minarchist or authoritarian positions, and likewise some of the libertarian socialists fall back on authoritarian socialist positions.
There’s also a distinction between political libertarians and apolitical libertarians, and this distinction actually crosses over into the territory of both minarchists and anarchists. The side of apolitical libertarianism is best represented by the agorists, who make opposition to the political process and the use of direct action and civil disobedience as an alternative a key issue. The side of political libertarianism is best represented by the Libertarian Party and the Ron Paul movement. This distinction may also lead to the problem of anarchists falling back into functional minarchism or authoritarianism.
Philosophical approaches to libertarianism is fairly fragmented into numerous different sub-categories. Utilitarians vs. natural righters, egoists vs. universalists, left-libertarians vs. right-libertarians, thin libertarians vs. thick libertarians, libertarian socialists vs. free market libertarians, anarcho-capitalists vs. individualist anarchists, and so on and so forth. The logical implications of libertarianism and wether or not certain values or compatible or incompatible with libertarianism is hotly debated. Most of the people involved generally agree on the same principles but interpret and apply them in different ways.
This creates a degree of vagueness that undermines any clear definition for libertarianism. In some cases, a false dichotomy or semantic ambiguity is involved and a reconciliation is to be made, and in other cases incompatible values are smuggled in by one side or the principles are not being properly defined, interpreted or applied by one side. The plumbline and/or thin approach to libertarianism also creates a lot of vagueness in terms of clearly defining libertarianism or putting it into its proper context. On one hand, libertarianism is portrayed as a “big tent” that is open to any set of values, while on the other hand certain incompatible or tension-creating values are smuggled in.
Suppose I went around calling myself an “anarcho-monarchist” and advocated a monarchy model as if it was compatible with libertarian anarchism. Would anyone really take such a thing seriously? While perhaps such a model would be on a smaller scale than the current state, would it be compatible with libertarianism? Does literally any value become legitimate so long as it’s implemented on a smaller scale? It is clear to me that the answer to all of these questions is a great big “no”. While decentralization is generally preferable to centralization, decentralization only has to do with size and scope rather than content. It has nothing to do with content. A mini-theocracy is still a theocracy, a mini-monarchy is still a monarchy, and a mini-state is still a state.
In some sense, the problem is that there is not enough decentralization in such examples. That some people actually advocate such things under the banner of libertarian anarchism perplexes me. The very principle of the values in question are authoritarian in nature, so it makes no sense to expect them to mix well with libertarian values. Such values very overtly undermine libertarianism and anarchism. So it should be clear that libertarianism cannot be combined with any old set of values without risking undermining itself. Authoritarian libertarianism and conservative anarchism are simply contradictions in terms.
This is not to say that pluralism does not have its place in the context of libertarian anarchism. But that’s precisely where the pluralism is: in the context of libertarian anarchism. It is not a completely arbitrary pluralism, it has qualifications. It is absolutely true that many different forms of voluntary association can co-exist peacefully in a libertarian anarchist society, but this is conditional upon a clear understanding of what it means for something to be voluntary or coercive and what constitutes the proportional and just use of force given various different circumstances, or by the very least, a generally live and let live attitude. This means that questions of philosophy and culture are not completely irrelevant to libertarianism. Anarchism without adjectives definitely has it’s context though, and its main limitation is that it cannot be compatible with values or systems that inherently undermine the overall anarchist principle involved.