Actually, I was talking about the Aztecs and Maya, and while the modern idea of a nation with a fixed ethnic makeup (something that applies to very few states in the world) might not have been inevitable, they certainly had the idea of states, and boundaries, and wars over said boundaries.
Applying Western concepts to people not from the West tends to get messy. The indigenous people of South and Central America did not have an Enlightenment inspired nation-state with a citizen supported political and military structure. At the time, even the European countries didn't have these.

I can't argue with that, I just learned that many of the stories were false from one of my professors, who is considered one of the country's leading experts on Latin America. Well, that and things I learned and read while living in South America. That doesn't mean I"m right, since people, even profesors, can pick ideas from all sorts of questionable sources, and even the good sources disagree at times.
One thing you learn is that no one really knows anything for sure. But, there tends to eventually be a consensus about things. And while details and degrees may be debated, there seems to be a general agreement that the Spaniards murdered, raped, and overworked the indigenous population of South and Central Americas, as well as the Caribbean.

Interesting, I was also taught in university that that was also quite possibly a myth, and at the very least much less common than supposed. Never mind that the common cold and several other diseases than small pox caused most of the deaths, and that the diseases spread quite quickly in areas where Europeans had little contact, without the need for a primitive, mostly ineffective form of biological warfare...
I think there is enough evidence to suggest that it did happen. True, a lot of it was by "accident". But, my original point was, that it happened because one group sailed over and conquered another group.

So, in your hypothetical world state, would travel be so restricted that none of the people from the other three inhabitants of the world would ever have made it to the Americas? Or, in a more modern example, no travel from Africa to better contain Aids and most of the world's current cases of smallpox, no travel from Asia if there's any risk of bird flu spreading?
I'm not trying to rewrite history. In my hypothetical world-state, it starts in the future, not in the past. I live in reality and try to change it. I don't try to rewrite history. Not sure where you were going with that one Zim.

I'd say with a common world government and a common economy diseases will spread not only much quicker than they had managed to back then, but probably even somewhat quicker than today. Either that, or freedom would be much more restricted for our own "good".
Not sure how your connecting those things. You can have disease policy at the same time you have a global spanning government. I feel your mixing apples and oranges here.