Nauru is a nominally independent island in the Pacific Ocean that once enjoyed a very high standard of living owing to its minuscule population (today less than 15,000) and huge riches of phosphate (aka high-quality bird poop). These days the interior is entirely desolate as phosphate supplies have largely been exhausted, the government is highly unstable and practically bankrupt, and Australia calls most of the shots. The sovereign wealth fund evaporated through bad investments and embezzlement by corrupt officials. The population suffers some of the very highest rates of obesity and diabetes in the world and does not have the facilities to deal with these issues. All residents live on the coast, which is also at risk due to rising sea levels caused by global warming.
The future is very much in doubt, and Nauru serves as a cautionary tale to other societies based on a mirage of endless prosperity.