EU enlargement is a complex and challenging process. It involves a number of steps, including:
1. Application for membership: A country that wishes to join the EU must first submit an application to the Council of the European Union. The Council then decides whether to grant the country candidate status.
2. Candidate status: During the candidate period, the country must implement a number of reforms to bring its laws and policies in line with EU standards. These reforms may include changes to the country's political system, economy, and judiciary.
3. Negotiations: Once the candidate country has made sufficient progress in its reforms, it can begin negotiating with the EU on the terms of its accession to the EU. The negotiations cover a wide range of topics, including the country's financial contributions to the EU, its representation in the EU institutions, and its adoption of EU laws and policies.
4. Accession treaty: Once the negotiations have been successfully concluded, the country signs an accession treaty with the EU. The treaty outlines the terms and conditions of the country's accession to the EU.
5. Referendum: In most cases, the accession treaty must be approved by a referendum in the candidate country.
6. Ratification: Once the accession treaty has been approved by the referendum, it must be ratified by all of the EU member states.
7. Accession: The country officially joins the EU on the date specified in the accession treaty.
The process of EU enlargement has been ongoing since the 1950s. The most recent enlargement took place in 2013, when Croatia joined the EU. There are currently two countries that are considered candidate countries for EU membership: Montenegro and Serbia.