When I think about the future, I often imagine a world where the traditional roles of nations have trickled away to be replaced by allegiances formed by interests, not geography. There are strong trends that point in this direction. Even now, many companies have become global conglomerates, their scope well beyond the limits of any borders. Look at the EU. Countries which for much of the last millenia were constantly at war with each other, have now opened their borders to each other and share in a common currency.
Even as individuals, we often find ourselves traveling between countries almost at will. More importantly, we communicate with individuals in other countries at will. You can Skype with a stranger in Russia just as easily (or more so for some) as you can approach someone at the corner coffee shop. The associations with which we identify ourselves can align by interest rather than geography. How many facebook groups can you join? Also, this is just the beginning of a trend. Who knows what will happen?
For instance, you usually rely on your local government for services (like police, fire, etc.). But some things are privatized like car insurance and health insurance. Now many of those companies are international companies. So you could be under the same insurance umbrella as someone in Germany. In fact, it is very likely that in some ways, you are already under the same financial umbrella (those banks are BIG).
And then there's the counterpoint: geopolitics.
I recently picked up a book called The Next 100 Years by George Friedman. Now any book that is a prediction of the next 100 years doesn't sound like it should be in the NON-fiction section, but in the 10% of the book I glanced through, I did get a good sense for how he thought, and the method he was using to make predictions. Primarily he thinks of the world as nations that make limited decisions based on protecting their national interests in the context of the global environment. It's quite different than my own approach, and thus, quite fascinating to me.
From his standpoint, the next century will be "much like the last one" except in every detail. There will be wars (US vs Japan, Turkey, and then Mexico this time) due to the inherent conflict of interests between the powers of the world. Meanwhile, I tend to believe that the next century or two will begin to alter the paradigm of history and hope that our pattern of global warfare will change.
Whether you believe his predictions or not, I think the book is worth a quick read through. His central thesis that the U.S. is and will continue to be the dominant superpower throughout the next century is certainly an interesting (and very probable) stance. In this viewpoint, things like military power, geography, and control of both the Pacific and Atlantic trade routes figure more importantly than any possibly political action. In particular, he gives a great analogy of how the US is like an adolescent, just starting to grow into its power, and clumsy and insecure as it does so. If the US is truly only beginning to reach its dominance, that gives us, the citizens of the most powerful nation in the world, the opportunity to have a dramatic impact on the rest of the world, hopefully for better rather than for worse.