Further explorations through questions
It was recently asked, on fedi:
If the world adopted anarchy, and small self-governing communities became the norm, what stops community A from attacking weaker/wealthier community B? What stops resource-rich places surrounded by arid land from overcrowding? What stops some charismatic person from leading a society into a more statist structure, thus allowing it to grow larger than it naturally would be? In other words, how is global peace to be kept and what stops tribalism from breaking out?
Let's take them one at a time, because each of these questions asks something distinct which is often lumped together due to the history of lumping them together.
First and foremost, “what stops community A from attacking weaker/wealthier community B” is going to differ from community to community. Deterrence would not disappear; cameras, sidearms and local security companies would deter the low-level violence and crime no different than police do now. But beyond that, agreement between community A and community B would likely be the most common reason; mutual voluntary agreements with all your neighbors would a must, regardless of the size of your property or collected properties. You don't go into your neighbor's garage and steal his tools just because he's better off than you, and those that do can be deterred.
It's also important to note that word of mouth is not something that would evaporate; if anything, your local “social currency” would be more important than ever, and taking to violent recourse against your neighbors could cost you materials and supplies that you need, because the person with whom you're doing business doesn't want to do business with you anymore.
It is to say, nothing as a form of greater authority would stop community A from attacking weaker/wealthier community B, but the costs of making that attack can quickly become far greater than the gains made by such an attack. Not to mention, you will then have four neighbors who know you are violent and unjust, and will hesitate less when it comes to defending themselves against you. But this isn't much different than what we have right now, even on the geopolitical scale.
Let's take resource-rich arable land, as per the first sub-question; do you live on a farm? How far do you live from arable land? For the majority of people it is greater than 100 miles. Most people do not live on arable and resource-rich land; as always with the Pareto principle, it is a small minority that holds and works the majority of these resources. But that wouldn't matter, because shipping and transport logistics solutions of all scales only becomes more important in a world oriented toward the community, the local, or the individual — everyone needs to both move product, and obtain supplies, as is their responsibility in the freedom of having none above you.
Most people will prefer to live close to other people; and in these areas it's extremely likely that you will see warlords arise from the massing of people seeking assistance. And if people in range of their collected territory aren't careful, they could be easy targets for those warlords. But, and this is a place where I haven't seen or read a lot of discussion so take this as purely hypothetical, the coalitions that form against would hold the guerilla and tactical advantage once they coalesced in response. And they would coalesce in response; not as a unified army but as homesteaders protecting themselves and their rights. As with any regime-change, including one that ends in no regime at all, there will be a spike in crime that will rapidly be addressed in wide and varied manners, bringing crime back down.
But there's a greater point that I see here; an absence where one might see requirement, given the history of the world and its endless territorial and ideological conflicts. That requirement isn't one with which I agree, however; with the correct incentives and disincentives distributed as responsibility across all people, those being security, economy, and community, you drive down the potential for conflict to the point where it is so small, or so costly, that when it does occur it is rare, and leaves all people wiser for how to ensure it does not happen to them, and thereby does not happen again.
There will absolutely be charismatic psychopaths; but there will also be, as they say, a gun behind every blade of grass in addition to a camera behind every awning and tree. They might be able to take ten, twenty houses; but like Go their actions only surround themselves further by their opponents' zones of control.
Anarchy does not change human behaviour; it acknowledges it directly, for its shortcomings and its strengths. War and warlords will not disappear; it's still up to everyone to maintain the society they so voluntarily invest themselves in.