amaevis, I believe I understand your point. And that you understand mine.
However, you've got some of your American history incorrect.
The original Confederation of American failed because participation of the individual members states voluntarily participated to their own degree at the Federal level. Funding, enforcment, laws, trade, etc. This is the situation we have with the current UN.
Where you go wrong: It was the creation of the United States of America that corrected that. This new government had a federal government that had actual powers. The division was clear between States and Federal powers.
The national identiy was forged by the Telegraph (linking the west coast with the east coast in communications so that the west coast went from being weeks to months out of touch to being just a few seconds behind the events of the East, and visa versa), and the Transcontinental Railroad (linking the west coast with the east coast in travel, so that people and goods could travel in just a few days between the two, rather then the several months it used to take).
The American Civil War was about what was supreme, the rights of the People, or the Might of the Federation. The People lost that one. For those of you educated in the American public school system, this is what Licoln's own statements and writings have said--- that it was about subjagating the will of the People to the Power of the Federal forever. That was why he couldn't let the Confederate States have their way. He stated that fighting the Civil War was the death of the true country of the United States of America, as the balance of power between the People and the Government was going to be broken forever; one invariably had to become a slave to the other. And for the sake of the remaining *rulers* (politicians and rich Americans invested in the current American power structure), it had best be the Union that won. Otherwise, all the other states would eventually just be able to opt out, and the Federal rulers would be no more. Indeed, he refers back to his decision to firmly throw destroy the founding principles of America and that the new Union was nothing more then dictators maintaining their power when he talks about forcing Maryland to stay in the Union.
I don't believe in throwing away valuable, non-renewable resources. The UN is just that. The nations of Africa do not take their various businesses and disputes to the UN. Why? Because it's quicker, and better for them, to take it to their own local Federation. Just as the US, Canada, and Mexico settle their own disputes. Or for that matter, just as France, Britian, and Germany take their issues to the EU. Now, these larger blocks can and do settle their own matters just fine between them, with no UN.
In governmental issues, you always want to go to the smallest layer of beauracacy as necessary. The UN is not a natural formation of the smaller international blocks. It is instead and overblown version of the League of Nations. It's LoN 2, and just like most software sequels, it is more bloated and more costly without adding many new features.
I think that if we last long enough as a civilized species, Earth will form a World Federation. But one where the rulings of the top are binding, and one in which the soldiers of the WF is dispatched to any place a smaller member nation gets uppity. It seems to be the logical progress of continued trade and advances in communication and travel. The truth is that cooperation creates a better life for us then not cooperating. And we will continue to increase our cooperation until just past the point it continues to benefit us. Barring any apocolyptic events, anyways.
The UN isn't a logical growth. It isn't interested in advancing the state of humanity. It serves as a mouthpiece for nations to bloviate and threaten each other, and clearing house to hold a few of their "ruling class" relatives. This means that it cannot serves the needs of humanity effeciently. It isn't the most efficent bureaucracy it can be. It is exactly the opposite because it's purpose is not to serve humanity. WHO, for instance, is a bigger detriment to world health then it is an advantage. Indeed, it is trivially easy to find where the UN has harmed the world. It is incredibly difficult to find cases where it has helped. It's easier to find examples where America or France or the UK has helped the world then it is to find where the UN has helped. Now, if something as small as France or the UK can do more good then the UN, why is that?
The UN doing stuff does not lend an instant air of acceptability to anything. It might sound reasonable on the idiot box, but most people I know that spend their life working in all manner of places around the world inform me that the UN is generally considered a joke, or worse, on the side of the "bad guys". There are some areas where the UN is seen as a good thing, but from what I hear, there are few and far between.
You shouldn't presume that the exchange of media, communications, tv shows, etc will create a homogenious society. If that was going to happen, there wouldn't be such a thing as "black culture" in the US. Or "West Coast". Or "Feminist". Or "Trekkers". Or "Furries". Or "Goths". Look at any school, and you will find that we humans naturally group and develop culture. We always differentiate ourselves from others. It's how we are. But we will cooperate to make gains. Keep in mind that the more channels of communication people have, the more groups we fracture into, because we are actually sharing less experiences, and therefore have less common points. In the US during the 50s and 60s, TV networks gave us all a common experience. But now, when you have 500 or more channels to choose from on your cable or dish, as well as all the recorded media (DVDs, Direct Streaming, etc), we are becoming more and more fractured. Things like the internet are just speeding that up, not bringing us together to form one big world culture.
Profiteering does give us the tool for a united world. But it isn't the tool to maxlmize protecting the non-renewable aspects of our planet. Big governments can do that, but they don't care if you have toilet paper that is incredibly soft and scented pine fresh, or that you have a small roll of sandpaper. Governments just care that you don't riot in such force that you overwhelm their guards, storm their homes and offices, and execute them for the excesses they have indulged in while your children have suffered and died needlessly. This is, again, the nature of the Zero Sum Game.
If you see the UN as man's hope for the future, then you are more optimisitic than I. I forsee the UN getting abandoned in favor of a future world trading federation composed of regional blocks (the EU, Americas, Pacifica, Africa, Trans-Arabia, and the underwater trading blocks making up the deep water communities in the Atlantic, Pacific, Indian, and Artic Oceans). It will, however, get in trouble for forcing the orbital communities to bow down and kiss its feet. Ultimately, I forsee the World Federation itself being forgotten by the Stellar Community that emerges. Eventually, the Earth is going to be a deep gravity well ghetto. What it becomes after that, I don't know. It depends on how cheap it is to go between orbit and dirtside, and if there is anything down here worth trading for and taking orbital. But don't despair--- the vast majority of humanity will be living the good life, scattered throughout the solar system. And beyond, given enough time.