How Exactly Do New Countries Come Into Existence?

Upon first sight, and at least in part, it would definitely appear that the existence of “internal” division is at least one major cause, if not the cause.

It seems as though country’s either ultimately “divide” into two new countries, or absorb into each other (by peace or by force?) where they also act as a sort of unifying agent as well.

Do country’s ever really die?

Or do they just multiply?

Might this have anything at all to do with the infinitely replicative, and multiplicative nature of thought?