No one really, that is kind of the thing. Human history has been a series of moments where when one government collapses, a new one is created in its place. Depending on who you ask, the [definition of a government][1] is [“the system by which a state or community is controlled or regulated”][2]. According to Enlightenment thinker [John Locke][3] in philosophy, if [a system regulating a community provides three things][4] (law and order, protection of property rights, and enforcement of contracts), then it counts as a government. Sources like Encyclopedia Britannica refer to [militias as  political institutions with many informal communities and nations having militias as their governing bodies, so even those can be seen as governments][5]. With these definitions, a simple clan or neighborhood watch, or group of people forming a citizen’s arrest group would count as a government as long as it protects the public against the many people who lack empathy and compassion or simply don’t want to follow the rules, those who would misuse private/public property, and guarantee that contracts are enforced instead of ignored by those who just don’t want to follow through. Human beings naturally form into groups since we need to [socialize or suffer negative effects][6]. When we form together, we create systems that enforce the rules and when the government collapses, no one can really stop people from coming together and creating their own system to fill the void: not without ironically forming your own group that fulfills the criteria of a basic government to stop people from forming their own government.


  [1]: https://www.lexico.com/definition/government
  [2]: https://www.lexico.com/definition/govern
  [3]: https://plato.stanford.edu/entries/locke/
  [4]: https://plato.stanford.edu/entries/locke-political/
  [5]: https://www.britannica.com/topic/militia
  [6]: https://www.verywellmind.com/loneliness-causes-effects-and-treatments-2795749