Personally, I see a world gov’t as inevitable, but probably 200 years away, with the process growing gradually.
First, the reason the US is stronger than the EU is because the EU is a bunch of disparate govts working against each other in many ways. The US and Europe are approx. the same size and both have abundant natural resources. But one can utilize the entire country’s resources for the entire country’s good. We don’t need to grow massive numbers of crops in New Jersey because they are easy to import from the midwest. And the midwest doesn’t need to focus on a huge film or aerospace industry because that’s based in CA and helps the entire country.
On the other hand, a film industry in England doesn’t do much good for the residents of Sweeden. They’re just not interconnected enough.
So I think one of the first steps is to have what we currently think of as separate countries in Europe band together into states under a single European leadership system with real power, and local issues would be dealt with by local gov’ts.
The arguement that separate cultures can’t work together in the same gov’t is an absurd one, IMO. Anyone who thinks that doesn’t realize how vastly different cultures in the US are regardless of a common language. Louisiana vs. Florida vs. New York vs. Kentucky vs. Washington. And as much as the political parties here fight, even the 2000 Election debacle was solved without violence. The conflict was all verbal and political, which was an amazing sign of progress. I despise Bush with a passion, but like him or not, I still recognize that he’s the country’s leader for the next few years, just as the right wingers had to deal with Clinton before him. Again, without resorting to mass violence when he won.
Another benefit the US has is a common language. Putting cultural differences aside for the moment, the whole point of language is to communicate with other people. A single international language would do more to unite the world than any other individual step could, though obviously much more would be needed. At the current time, I think the language would obviously be English. 100 years ago, had a global language spread, it would most likely have been French. Additional languages wouldn’t need to be removed, so long as everyone learned at least the agreed upon standard, whatever that may end up being.
And again, look at Canada vs the US or different regions in the US to see that shared language does not automatically result in homogenized culture.
So start with a genuinely unified Europe, add a century, and watch it grow. =)