The European Union: Questions and Answers
Congressional Research Service 6
Why and How Is the EU Enlarging?
The EU has long viewed the enlargement process as an opportunity to promote stability and
prosperity across Europe. The EU began as the European Coal and Steel Community in 1952 with
six members (Belgium, France, Germany, Italy, Luxembourg, and the Netherlands). In 1973,
Denmark, Ireland, and the United Kingdom joined what had then become the European
Community. Greece joined in 1981, followed by Spain and Portugal in 1986. In 1995, Austria,
Finland, and Sweden acceded to the present-day European Union. In 2004, the EU welcomed
eight former communist countries—the Czech Republic, Estonia, Hungary, Latvia, Lithuania,
Poland, Slovakia, and Slovenia—plus Cyprus and Malta as members. Bulgaria and Romania
joined the EU in 2007, and Croatia acceded in 2013.
To be eligible for EU membership, countries must first meet a set of established criteria,
including having a functioning democracy and market economy. Once a country becomes an
official candidate, accession negotiations are a long and complex process in which the applicant
must adopt and implement a massive body of EU laws and regulations. Analysts contend that the
carefully managed process of enlargement is one of the EU’s most powerful policy tools that has
helped to transform many European countries into more democratic and affluent societies. At the
same time, EU enlargement is also a political process. Most significant steps on the path to
accession require the unanimous agreement of the EU’s existing member states. Thus, a
prospective candidate’s relationships or conflicts with individual members may influence a
country’s accession prospects and timeline.
The EU currently recognizes nine countries as official candidates for membership; all are at
different stages of the accession process. Joining the EU typically takes many years (if not
decades). Montenegro and Serbia are the farthest along in their accession negotiations, and
Albania and North Macedonia officially began negotiations in July 2022. Turkey has been a
candidate country since 1999, but its accession negotiations are stalled amid heightened EU
concerns about democratic backsliding in Turkey and other tensions in EU-Turkey relations. The
EU named Ukraine and Moldova as official candidates for membership in June 2022, Bosnia and
Herzegovina as an official candidate in December 2022, and Georgia as an official candidate in
December 2023. The EU regards Kosovo as a potential future candidate (see the Appendix).
The EU maintains that the enlargement door remains open to any European country that fulfills
the EU’s political and economic criteria for membership. At the same time, some European
leaders and publics have been cautious about additional expansion, especially to Turkey (given its
large size, predominantly Muslim culture, and relatively less prosperous economy). Concerns
about continued EU enlargement have ranged from fears of unwanted migrant labor to the
implications of an ever-expanding EU on the bloc’s institutions, finances, and overall identity.
Assessments of weakening rule of law in several existing EU members also have contributed to
decreased enthusiasm for further enlargement.
Russia’s war against Ukraine has boosted political and public support across many EU countries
for EU enlargement to Ukraine and other aspirants. Germany, France, and some EU leaders have
called for significant reform of the bloc’s structures and decisionmaking processes to enable a
larger EU to function effectively. Other EU member states and officials are reluctant to engage in
another major EU reform effort, a typically fraught and prolonged process.