There isn't a national superpower anymore, and that may be a good thing. No one can predict the future, but I can't see any nation ever being as globally relevant as the U.S. was in 1945-95. That wasn't just the peak of U.S. power but also the peak of nation-state power. If I'm right, no national government will ever attain it again. Not the European Union (technically a multinational government), not China, and definitely not India. I think China will be doing very well economically in 2100 (and people will be surprised to learn about the extremely widespread 20th- and early-21st-century Chinese poverty) but I think the influence of national governments will have waned by then.
I'm actually pretty bullish about the long-term American future, because I think the global trend is not only positive but going to accelerate in the next 20 years. I think the Bush years were a nadir, and I think we're in a long U-shaped valley, but I think the 2020s will be slightly better than the 2010s, which will shape up to be better than the 2000s were. "Decline" for us is going to look like it did for the British: the average Briton is still a hell of a lot better off (happier, wealthier, and healthier) in 2012 than in 1900. People don't actually think about national dominance much when they don't have it, and by 2050, I think that concept itself will be pretty well outmoded.
To put it frankly, I don't care if the U.S. is geopolitically #1 or #14 in 2050, but I hope they've done something about cancer.
I'm actually pretty bullish about the long-term American future, because I think the global trend is not only positive but going to accelerate in the next 20 years. I think the Bush years were a nadir, and I think we're in a long U-shaped valley, but I think the 2020s will be slightly better than the 2010s, which will shape up to be better than the 2000s were. "Decline" for us is going to look like it did for the British: the average Briton is still a hell of a lot better off (happier, wealthier, and healthier) in 2012 than in 1900. People don't actually think about national dominance much when they don't have it, and by 2050, I think that concept itself will be pretty well outmoded.
To put it frankly, I don't care if the U.S. is geopolitically #1 or #14 in 2050, but I hope they've done something about cancer.