Today we have independent nations trying to co-operate. Before you had few strong countries and the rest of the world was one big colony. Before that kingdoms were all the rage. And of course empires. So it's clear the face of the global political scene keeps changing; what's next? I think we'll have few giant nations. No more small island nation crap. This will be the case when sea levels rise and coastal nations with bad economies will be forced to join in with their more powerful neighbors.
I think you are incorrect. Large empires always fall. You are just describing different attempts at large empires. The problem is that the more people an authority controls, the lower the ratio of people it actually represents. Smaller local governments will always work better -yuri
Were on the path from 7 billion to anywhere from a doubling to 30 billion by the middle of the century depending on who's figures you are looking at. There simply is not enough resources and all the growth is happening in poor countries practically. Expect the future to be one of a over populated world, famine, massive water shortages, and endless wars over all of that. Whats great is we all have a front row seat.
The important thing is that, in all situations, hegemonic power always exists. Right now the US is hegemon, during the cold war we had a bipolar world, prior to that the UK was hegemon. In the less globalised world, athens was a regional hegemon, persia, mongolia, rome, china, spain, etc etc... One or more hegemonic powers will always rise to the top because international anarchy will always exist and states will always seek to maximise security at the expense of other states. The systems by which states are governed often changes, economic conditions change, cultures change, but realpolitik doesn't, it's constant. You might be interested in reading Fukuyama's The End of History and the Last Man, and noting how utterly wrong he was.
I see individual nations maintaining their sovereignty to a degree, but it we will most likely see a continuation of coalitions like the EU forming and eventually becoming consolidated under a banner of 'economic cooperation', 'shared democratic principles', or something along those lines. These coalitions will eventually adopt the same currency and tax regulations and immigration regulations (as we are seeing happening already), and they will basically be the same country, but with a different name and different faces in government (also, the spread of English and access to translation technology will make language barriers even less of an issue).
Maybe war and famine will ensue until 40% of the world population is wiped out. The remainder will rebuild and just repeat history.