South Korea: The only middle power of its kind
SK is committing demographic suicide though, so whatever you think of its success, it has a pretty fatal disease.  It has the lowest birthrate in the world.This is going to cause significant economic problems quite soon, or they will have to open up massive immigration which will completely change the country.https://en.wikipedia.org/wiki/Low_birth_rate_in_South_KoreaHow does the developed world pull out of this type of tailspin?  Japan and other nations are also facing this exact same issue and we seem to be not paying attention to it.The core issue is that in most of the developed world, people do not have enough children.  And even immigrants in their second generation and beyond also do not have enough children, as such it appears to be a cultural/way of life/society norms problem.  It is as if the developed modern world is currently designed as a population sink.This is going to be one of the grand challenges of the 50 years.