Some countries, like Israel or Finland, are not likely to exist for very long, because if they are ever in a weakened state, they will be quickly overrun or assimilated and be unable to make a comeback. And everything runs into problems at some point. (Incidentally, I think it’s more likely that Finland will disappear into the EU than Russia.)
Other countries, like Russia or China, will probably exist indefinitely, because even in a weakened state they are next to impossible to truly wipe out, both due to expansive geography and culture.
Finland is a classic borderlands country, and I sometimes think of it being that way in time too – occupying a brief window from the dawn of nation-states to its end sometime in the future.
This has something to do with the Lindy effect, whereby a long history suggests a long future. Even though Switzerland is small, it has good chances judging by a ~700 year history of its confederacy that hasn’t been extinguished by historical events yet.
