Does anyone believe that the natural progression of the world is a total open door policy?

The EU is inducting more and more countries into it, making it easy to move country around Europe as long as you are a citizen of an EU country. The US also developed into making 50 states 1 country. Many countries have joined with others so that they have special partnerships where they can move into each other freely. So, does anyone think that the world, given time, will become just one big country, or even just turn into something similar to EU, like a World Union, where all wealth is shared (not like communism) but where Superpowers will also provide for the poorer nations?