The article "European Union Enlargement: A Comparative History" looks at how countries that joined the EU between 1973 and 1995 have interacted with Europe since 1945. The researchers studied the European policies of the UK, Denmark, Ireland, Greece, Portugal, Spain, Austria, Finland, and Sweden to see how they have influenced the EU. They found that different countries have taken unique paths towards EU integration, showing that one-size-fits-all theories don't fully explain the process. The book suggests that the newcomers have brought diverse perspectives and experiences to the EU, shaping its development in various ways.