How small would a planet have to be for one world government to inevitably emerge? Do you see that happening with Earth in a few millennia?

A single country planet.

Maybe possible with a loose federal or feudal structure

define "government"
is the UN one world government? if it is not authoritative enough, where is the dividing line?

It's not possible in a representative democracy, you may think that if the USA in theory conquered the whole world we would have a "one world government". But even then the identity of that government is constantly changing and up for debate under the current system that allows voting in of new reps, constitutional amendments, etc. So you never really have one government because the system is in a constant state of flux/change.

It's more sci-fi but a singular government would be something like a coded set of rules that cannot be changed and is not controlled by ordinary humans. Like being ruled by a long-lived king empowered by genetic engineering or by a computer.

>>211882964 (OP)
I think it's a matter more so of technology expanding the range a state can effectively govern

>>211882964 (OP)
>How small would a planet have to be for one world government to inevitably emerge?

How big a body a government can effectively govern is entirely determined by developments in transportation and communication. The fact Ontario can call, or fly, anyone, and anywhere, within the country (despite how wide Canada is) in a few hours makes the government "possible". The next big issue of our era to overcome though is aging and population: the more people you have, and the older they become, the more dependents you have, the more an exponentiating demand they put on the governments ability to just keep track of its' own population.

With our own current level of technology we could probably govern half of the planet under a single government, but probably only a little more than 10% of the human population effectively?

>in a few millennia
Lol, I give it two decades

>>211882964 (OP)
You focused on the planet size, but I have an idea that the planet's rotation speed also makes it possible : slower it rotates, wider a country can be, because slower planetary rotation makes the time of transportation within its territory less significant to the day/night cycle.

>>211882964 (OP)
>>211882980
only feasible if there is an homogeneous starting population that don't have any big racial, religious or political beliefs while also keeping a close relationship between the high and low social strata

>>211882964 (OP)
it has very little to do with the size of the planet and far more to do with technology and diversity of peoples

>>211882964 (OP)
It will never happen. If all the world disappeared, aside from Australia, this one world government would split up eventually. Factionalism is an inherent feature of human societies. Humans band together against other humans, and without that, any political structure begins to unravel

It already happened in 1969, every person in the moon was subject to the same goverment

>>211882964 (OP)
It'll happen but with racial subdivisions