What sci fi books or stories have ever been written (if any) which explore the possibility of having nations, with individuals typically being citizens of just one of those nations each, but where the nations aren’t geographically defined. In other words, within a single geographic region you might have three different nations, all the citizens of those nations being jumbled together, with no particular geographically defined neigborhoods or anythign like that associated with particular nations.
The Diamond Age? The nations are called “phyles” and while they often have protected territories all over the world they’re not geographical countries as such.
(What you’re describing sounds a lot like anarcho-capitalism by the way.)
Snow Crash, too. And I think Eastern Standard Tribe, by Cory Doctorow.
In Snow Crash, also by Stephenson, most people appear to be affiliated to various franchises, rather than thinking of themselves as citizens of the USA; there is a government but people tend to forget it exists as it doesn’t particularly affect them…
Jennifer Government by Max Barry also uses a similar idea, iirc, although naturally Jennifer does, in fact, work for the government!
Bruce Sterling’s latest, The Caryatids, is post-national with, I think, three ideologies you can be affiliated to.