The article discusses how the European Union decides to let new countries join. It looks at the steps involved in this process, like association, pre-accession, and accession. The EU has rules and procedures for new members to follow. It also talks about agreements the EU makes with other countries, like the European Economic Area agreement. Enlargement is used as a way for the EU to control its foreign relations. The article also talks about how the EU sets conditions for new members to meet before joining. After 2007, the EU became tired of letting in new countries, and there are limits to how successful this process can be.