alright ok, you can be apart of the nation. (UCN is like United Nations just to clarify).

imma give out lore for avoidance of misinterpreting Arkania

Arkania is the main Leading Nation of the United Civilization Hence the name United Civilization of Arkania. It has many Planets in Control with other civilization sometimes and being apart of it means your apart of the UCN with your own Military Force on a different planet

for example. One of the existing planets of Arkanian territory Planet Kankora can be its own Nation/Government while under rule of Arkania. If the said Planet wants to be un-aligned with Arkania then Arkania (Or me). It will depend if its fine, understandable, or threatful. Do note that Arkania is neutral and will not be a conquere type. But you can be your own type of nation

In short
You can join Arkania as one of its Joint Civilize Nation under its rule and you can have your own Space group and control on the nation and its decision.

(sorry if im also a bit serious. I mean its roleplay anyways)