What is the smallest unit of government I can participate in?

What is the smallest possible unit of government? The problem with smaller governments is that the structure emerges very differently is various places and is legally defined in all kinds of unique ways across states and countries. I aim for this list to be generally right, but I think a lot of it is certainly up for debate. From Smallest to Largest: Commune / Building (Co-Op, Apartment Council, etc.) I really debated about the ordering of these two because they can have more members than each other depending on a couple of different factors. Neighborhood / HoA Municipality Village Town City Township County State Country Political Union (e.g. European Union) World (Has never existed) The UN has no lawmaking power for instance. The International Court of Justice (ICJ) has significant legal authority but lacks independent enforcement power. Its judgments are legally binding on the involved states, yet the court must rely on diplomatic pressure, voluntary compliance, and the UN Security…