I have another question re: all this raised by a friend's daughter who suggested just adding Mexico as a 51st US state. Interesting idea, but the irony is that Mexicans are also patriotic, even many of those who sneak into the US illegally. Human nature is weird! So although it could be a good way to raise up all of Mexico into a financially viable state, I can't imagine it could happen.
Now making all the world a single nation: That would be interesting. Sort of using the EU model on a grand scale.
I wrote my first letter to a president when I was a little fella, to Reagan. In it I suggested that we form the International Peace Force, a military composed of a certain percentage of every country's standing military, supported by those countries. Its mission would be to stand as a true world police force to prevent and stop things like ethnic cleansing, wars, and so forth. I thought it was a great idea, because why would anyone oppose an end to unjust wars and ethnic strife? A side benefit is that militaries would shrink, because what nation would want to sponsor a force that didn't really belong to them. Of course, I got back a form letter thanking me for my interest in the president, and thus began my decades-long education about exactly how responsive is our government.
So: What if every nation was instead a state in a larger United States of the Earth? Your thoughts?