One of the fundamentals of how a project as large as IB has become is described by Ytterbion's Special Rule of Parallel Creation. First, a little about Ytterbion and his rules.
Ytterbion was an ancient philosopher who lived in some distant past or golden age in some realm of the imagination or other. As a philosopher, much of his surviving writings were bombastic and tedious twaddle and were probably discovered by removal men as being used as wallpaper in a flat in Battersea. Even so, Ytterbion came up with rather a curious scheme of Spheric Creation, sort of like Wenedian nesting dolls, but with a few more dimensions. One of the keys to his philosophy ran thus: "This world was created by a being we call a God, who came from Outside; he in his turn inhabits an unfathomable world which in turn was created by yet another and greater divine being. In his turn, when the Thinking Man concentrates his attention to the Within, he may call forth into existence a world and thus become its God."
He then formulated several highly philosophical rules:
1. The God of Creation is the God Within.
2. The Gods created us from the stuff of the Universe; we created the Gods from the stuff of our hearts.
3. The polyform world is the Place where all creations find expression.
4. Each Act of Creation undertaken *here* is sublimely linked to and reflected by a realisation of the Act of Creation in the Elsewhere.
5. The polyform world is not merely a place: it is that which all places are places in.
6. The Here is the place all things strive to reach; yet they move not, for the Here is the place they always were.
7. The Rule of Reciprocal Creation: the Act of Creation undertaken *here* grants rights to the created and obligations to the Creator.
So, what does this have to do with Ill Bethisad? Apart from our thinking of this secondary creation as having a "life of its own", per rule 4, we have also taken quite seriously Ytterbion's Special Rule of Parallel Creation which runs thus: "The Act of Secondary Creation can also yield a world parallel to that of its primary; the overall history and culture of *there* ought to be similar to that of *here*." In other words the things that happen in IB ought to be familliar to those of us living *here* in the primary world.
That means that a lot of countries get imported in toto from *here* to *there* without any actual thought. Also, countries *there* tend to take on archetypal roles that are familliar from *here*. Florida-Caribbea, until its demise, was basically going through a phase similar to that of the USA in the 19th century, right down to the strong nationalistic ideals and manifest destiny. SNORist Russia *there* plays the same basic part Soviet Russia did *here*: the "evil empire", though of a religio-nationalistic bent rather than a communistic bent. Naturally, the Federated Kingdoms and the Commonwealth they participate in play the same basic part the British Empire played *here*: Top Nation, light of Civilisation and Culture to a benighted world, leader of the Free World, guarantor of Liberty and Decent Society, &c. &c. &c.
See also articles on QSS, Ytterbion's Rules and the Cycle of Proposals for more on how IB works.