Nations, also, ascend or decline on talent. North Korea does not attract outside talent (and inside talent has no incentive to perform). Japan's decline could be attributed to the inability to attract outside talent once its curret talent market reached maturity.
Could one ascribe the dominance of the U.S. (and to some degree, other Western countries) over the last 30 years to attracting new talent? Over that time the U.S. attracted a greater percentage of the world's talent than any other nation. In fact, it probably has attracted over 30% of the world's mobile talent (highly talented people that move countries). Much of that talent came from the Soviet Union which declined (and eventually fell), a newly educated China, and a newly educated India.
But that incredible talent will likely not come to the U.S. in the future. Chinese and Indian innovators should be able to find more opportunities in their homeland than in the U.S. (though they still may study in the States). And much of the Russian talent has already left for the U.S., Canada, Great Britain, Israel, and other places.
This means the U.S. will attract less talented people from around the world and will have to concentrate on growing its own talent internally. But the U.S. is not very good at growing internal talent. Our educational systems are sub-par and few naturally born U.S. citizens go into engineering and sciences. (When I was an engineering student at UC Berkeley, almost everyone in my classes were immigrants or the children of immigrants).
It is not all despair. The U.S. is still the shining hill that will beckon hard-working people from all over the world who want a better life for their kids. And I don’t think the U.S. has to worry about turning into a North Korea. But we can easily paint a path to prosperous but slowly declining country.
Smaller countries like Canada or Singapore might suffer less because they can still take in lots of immigrants in greater percentages than the U.S. can support. But the world 30 years from now will look very different from the world today depending on where the world talent flows.