In less developed countries, the borders are where they can draw a definite line between themselves and a rival culture that would stomp them out. I feel that nations will continue to be necessary long into the future as a means to keep people from killing each other for governmental supremacy within a single state. Only once our prejudices have had time to settle down can we begin making moves to unite the Earth. Even then, I would propose that there be a system set up in the fashion of the United States. This is where there are still borders, but all the nations will be united together, cooperating with one another. The only fear after this would be Civil War. Disagreements plague humanity like fleas to dogs. Some things cannot be changed, opinions and ideals are two of them.
In order to have the most effective international community, nations are needed in order to govern the populations and regulate the resources and economies. Without these divisions, the world would need to act as one. Decisions would be next to impossible to come by because of all the conflicting views already developed. Without these smaller nations, populations will not be monitored correctly across the continents. Unfortunately, humans have divided themselves up. Although we are all part of the human race, we still see conflicts because of ideals. For now, because of this, we must retain nations in order to use all the different ideals. Until we started chipping away at these differences, nations are needed for today.
I think it's natural to hold onto the idea of nations because we're territorial and competitive as a species. However we are coming to a point where it's time to make a decision as our world grows smaller, do we come together to save humanity as a whole or will we continue to have nations like Singapore (a nation with little to no pollution) and China (where the air is so toxic it's like smoking 2 packs a day), they've taken different positions on the pollution in their nation but the planet doesn't care the pollution in China will still effect Singapore and the rest of the world. Now that's a very simple example but as we face bigger and bigger problems we need to have everyone on the same page and reading the same book, and right now our mindset is them vs us when it comes to other people from other nations when it's really us vs everything else in this huge universe that could stomp us out. Cuz after all who cares whose got the biggest country if there's no one left to live there
It really makes you think that as smart as we think we are that we still fight over trivial things as land and property. Most of the worlds problems exist because we do not work together as one to solve them. If we spent as much time as a team figuring out how to stop hunger as we do worrying about our facebook accounts this world would be a great place to live in with no worries.