I'm a student writing a research paper about 'European Integration and Enlargement: Expanding the Union.' I'm having some difficulty understanding some of the concepts and I was hoping that someone in this forum could help me out. Can anyone explain the process of European integration and why some countries have chosen to join the EU while others have not? What are the benefits and drawbacks of integration and enlargement? Are there any potential risks for countries that decide to join the EU? I would really appreciate any insight or information anyone has on this topic.