I was either seven or eight when I came to the conclusion that the earth can only hold so many folks. My teachers told us how fast China and India were growing. The population of the earth was growing faster and faster, and that growth was expounding on itself. Talk about a little kid getting scared. I went to school and brought it up to my teacher. She laughed and informed me "Yes you are right, but it would not happen during your lifetime, or your children's lifetime time". I think she was wrong, we are approaching it now.
In the past people were content with life in their little backwards countries, because they had no idea how the other parts of the world lived. Today thanks to TV and Computers they now know there is a whole different world out there, and they want their part of it. When they go out and try to get what they see either a religion, a dictator, or a repressive government stops them. So they develop the attitude, if they can not get it for themselves, then they want to bring the rest of the world down to their level.
This is where we are today. Either everyone who can is trying to get into then US, or they are wanting to bring us down to our knees.
OK if the whole world was under one government many people feel that would bring everyone together as equals. Everyone would be able to attain the level of everyone else. What they are unable to understand is that is has already been tried, it was called Communism. Did not work in Russia or China. Why do we want to try it again.