What's so bad about China and India overtaking the U.S.? It's not like they are going to start a nuclear war just because they think they can win. That's not how it works, seriously. If they have such strong economic ties with the U.S. and the E.U., there is no way they will ever want to start a war unless we make them think that they have to. They aren't insane warmongers, or they would have done it already.
Also, on all of the military questions, I think that you guys have failed to grasp that this isn't going to be the good 'Ol days of the early part of the 20th century, with superpower nation-states bashing each other over the head for 6 years like what happened in world war two. It's just that the common theme for the past fifty years has been a "dual superpower" conflict scenario, which just doesn't apply anymore. When China becomes the technological equal of the west (which it probably will), it won't be invading Taiwan or nuking Los Angeles. It will probably end up policing East and Central Asia, and maybe some other trouble spots in the Eastern Hemishphere like the Middle East, much like the United States does. I don't think they will make themselves into our adversaries because there is no advantage in them doing so. We will probably be working with China in some instances in places like Central Asia, where water shortage will become a major source of conflict (this is going to be a common theme in the 21st century. Water shortage will undoubtedly occur in many oil-rich regions of the world, like the Middle East and Central Asia). In other instances we may find our special operations forces meeting China's and there might be a few clashes here and there because our goals and the Chinese's goals differ, but I doubt that anything like an all-out nuclear war will ever occur between the U.S. and China unless things get really desperate. And no, they will not remain as authoritarian as they are now, but they probably won't become the consumerist culture that we have either. They will most likely strike a balance between the two, and the government in China will always be the most important institution, because the people of China will never be as wealthy by virtue of population as the West, but it won't matter because the Chinese government will still be able to channel the aggregate wealth of the country as a whole into military technology and R&D.
Personally I have my own scenario as to what will happen within the next 50-100 years, and it probably won't involve any major showdown between the U.S. and China, although there will still be many conflicts. I think that the small-war scenario is still the most likely outcome of any conflicts with China, and it will most likely take place in another country, neither the U.S. or China proper. I just think that all you guys are getting into a bunch over it when it probably won't be as big a deal as you are acting. You guys have to face that fact that the United States will not always be the 800 pound gorilla of the world, the United States will not always be the superpower that controls everything, protects everybody, and kicks ass all the time. Decline happens, and it's inevitable. Deal with it and move on. The China of 50 years from now will not be the same China as now, it's a given.
