Pride in your nation (to me at least) is so intrinsically linked to the modern nation state that I can't untangle it from nationalism. As such, it is always a tool for the powerful to override international class solidarity.

I can get if you're tied to and have positive feelings towards a culture that you identify with. But the nation tries to replace that connection to a culture by:

1. Not making it opt-out (becoming stateless is such a disadvantage, if it's even possible)
2. assimilating different cultures that actually don't have too much in common. E.g. Danes and Mecklemburgians have way more in common culturally that Mecklemburgians with Bavarians.