My take also. Small "d" democrats and small "r" republicans will disagree; small "l" libertarians will see the truth but most will be uncomfortable with where it leads.
If one believes it is just as immoral to impose the will of the majority on the minority as it is to impose the will of an individual on another individual, it's hard to see how any but the smallest group of individuals can ever form a just government.
While a consitutional republic comes closest, there are unavoidable flaws, most notably in the interpretation of the meaning and limitations of national defense and law-enforcement. Someone will be given the authority to make decisions about where to draw the lines, and many citizens will disagree with whatever lines are drawn.
I don't know if Fucetola is anarchist or libertarian, but I believe that national self-determination is at best misleading and usually evil concept from the libertarian perspective.
Individuals may voluntarily form collective enterprises in defense of their natural rights. The individuals may form such enterprises without regard to geographical location of the constituents or their ethnic, racial or cultural makeup. Those collective enterpises can go about defense of their client's rights anywhere on the planet. When such enterprises are chartered to operate inside a contiguous territory, they are called governments (or "the state"). The circumstance of a territorial mapping of the enterprise may be a practical convenience but it doesn't add or subtract anything from the rightfulness of its actions: when the enterprise defends individual rights, it is acting rightfully, and when it violates individual rights (of its clients or, more typically, someone else's), it is acting unrightfully. Similarly, the circumstance of common language, culture or ethnic stock may facilitate the forming of the enterprise, but the ethnic cohesion of the constituents is not a significant fact under natural law.
A government of a nation has no more naturally-lawful powers than a private security firm hired by any motley crew of clients. Thus the national government of a big nation does not have a naturally-lawful power to govern over an ethnic enclave if it is peaceful and wants to have its own government. At the same time the enclave does not have a naturally-lawful power to prevent an outside agent from enforcing individual rights. Thus, contrary to the conventional wisdom of national sovereignty/national self-determination, the US government may justly use force to restore American ownership of oil fields nationalized by the country where the fields are located; at the same time, the US government may not tell Texas (or a county in Texas) what laws to have as long as the lawmaking in Texas is consented to by the Texans and US citizens outside of Texas maintain their individual rights.
I disagree that the above is a recipe for geographical smallness and outwardly impotent government. As we discussed previously (Defense of Liberty: Just Intervention), a government may have an aggressive foreign policy and represent a large nation, as long as the rules of the social contract that empowers the government's warmaking are clear, opting out of the social contract (e.g. through emigration) is possible, and the goals of the government are rooted in individual rights.
Didn't seem to be a problem with our forefathers in 1776, the idea of a republic of and by the people satisfied the conditions of a just government, since then it has been a slow slide into the abyss.