I know I will be treated as an extreme futurist, but we live in this little tiny spec called Earth and we're all in this together. The idea that there are laws about environmental protection in one country and none in others, calls to the idea that we should just have a single unifying country called "world" and keep the current separation only for cultural reasons. The EU was a step in this direction but it seems th…
The world has gotten smaller and the effects nations have on each other larger. It's dangerous and it's not efficient. At the same time people have their local customs and laws (and spending habits). So let that be. But enforce bans on slavery, genocide, trade route monopolization, nuclear weapons, pollution etc. At an international level.
As it is, it seems national governments are in general problematic... both to local communities and to the global community. I think eventually they can be done without.