Yes, it gets complicated defining a nation if you want to get OCD about it.
However RW has all the tools to let you do so if you want. You can describe the physical geography of the nation with the various places topics. The people of the nation can be described with People topics, grouped into Cast Lists and attached where they are appropriate. More abstract things like the government and military organizations of the nation can be handled by Group topics, Group lists and again attached where they make sense.
For instance:
https://www.dropbox.com/s/pdn3iakqz7...35.25.png?dl=0