Setting:
I'm working on a scifantasy setting that has many of the "classic" monster tropes turned on their heads a bit/adds unique biology/ that sort of thing. The metacommentary is about assimilation. The general idea is that in the past, humans were part of the general food chain, but as humans became more technologically advanced, they destroyed most of their predators by accident or by actually going after them (taking a bit from Peter Watts' Blindsight novels, about how vampires were actually destroyed by the use of right angles which triggered seizures and 'outed' them so they could be identified.). All humans have now are "legends" and "myths" of the things that used to prey on them.
The few actual 'monsters' that are left, have let humans keep that disbelief going, but are having troubles now because there are so few of them and they have to be so careful about how they hunt or maintain themselves because humans are prey animals and they get explosively aggressive and over-reactionary if someone eats half-of a kindergarten (the homeless population are much safer targets... but you have to use the whole kill to avoid getting the wrong attention or starting up a witch-hunt/wild goose chase).
There's a couple of "supernatural" factions across various continents that have adopted isolationist policies, or have integrated themselves in human society to hide in plain sight, or have actually accepted that they're going to die out. The metacommentary is about cultural assimilation and such.
There's a couple of members in an isolation-based group that because of reasons, have become retaliatory and expansionist. This was initially done by buying up properties and taking over space in a "human business" fashion. They've now butted up against another faction that wants to remain isolationist. The problem now is, both sides have their own dragon. Dragons, in this setting, are quasi-eldritch creatures with bizarre reproduction, really long life-spans if they survive to adulthood, really esoteric motives, and if two fight it tends to make very noticeable craters.
One side is really pissing off the other. They are going to fight, and human authorities are going to notice.
The Question:
One of the dragons was fully formed around the Tunguska event in 1908, this would make her 110 years old today. This is much older than the current youngest country, South Sudan (formed in 2011).
My question is a geopolitical one. Would a dragon be able to claim "herself" as an independent sovereign nation? Like how Indian Reservations are independent countries, of a sort, within the United States. And what sort of obstacles would collectives like the UN or EU throw at her?
By Wikipedia the definition for a soverign nation is:
A sovereign state is, in international law, a nonphysical juridical entity that is represented by one centralized government that has sovereignty over a geographic area. International law defines sovereign states as having a permanent population, defined territory, one government, and the capacity to enter into relations with other sovereign states. It is also normally understood that a sovereign state is neither dependent on nor subjected to any other power or state.
I know she'll get challenged for being a physical entity. But, she has a defined home range that she purchased (through intermediaries like a corporation), she's older than some current countries, she has a population (albeit of semi-thralls) that provide infrastructure. She has a government, namely, herself and her thralls act rather independently for their community, she can also qualify as her own military to protect her borders.
I already know how humans would react to these supernaturals on an individual and group basis, so this isn't a question about "how would humans to react to a dragon queen." I'm really looking for something on the country-scale here.