Italy, a large car manufacturer, has a problem because cars are being replaced by public transport. No cars are allowed to drive, only by public transport can you get to a destination. This is a problem for car makers, it puts them out of business.
An example of when specialization caused a country problems is when Nigeria focused all of it's effort on the oil production. Agricultural products were not a priority so they did not prosper. Nigeria had to import agricultural goods to survive.
