Great Britain. The United States. Canada. Italy. Belgium.
These are nation states. And their future is unclear.
Nation states have historically provided 2 key benefits: The ability to pool resources for a common defense and a single market.
Globalization and the slow pacification of the modern states of the world are taking away much of that benefit.
For example, what exactly does Texas get out of being a state in the United States? What about British Columbia in Canada? What benefit to they get out of being part of Canada? What benefit does Scotland derive from being part of Great Britain?
I am not saying that these nation states are going to fall apart any time soon. But in the long-term, the forces keeping these states together is going to keep getting weaker until it's only inertia that doesn't split them apart.