Enlargement of the European Union

The EU's predecessor, the European Economic Community,[1] was founded with the Inner Six member states in 1958, when the Treaty of Rome came into force.

Accession negotiations are currently ongoing with Montenegro (since 2012), Serbia (since 2014), Albania (since 2020), North Macedonia (since 2020), Moldova (since 2024), and Ukraine (since 2024).

Negotiations with Turkey were opened in October 2005,[2] but have been effectively frozen by the EU since December 2016,[3][4][5] due to backsliding in the areas of democracy, rule of law, and fundamental rights.

This is based on the 1993 "Copenhagen criteria" agreed as it became clear many former Eastern Bloc countries would apply to join: Membership requires that candidate country has achieved stability of institutions guaranteeing democracy, the rule of law, human rights, respect for and protection of minorities, the existence of a functioning market economy as well as the capacity to cope with competitive pressure and market forces within the Union.

Membership presupposes the candidate's ability to take on the obligations of membership including adherence to the aims of political, economic and monetary union.In December 1995, the Madrid European Council revised the membership criteria to include conditions for member country integration through the appropriate adjustment of its administrative structures: since it is important that European Community legislation be reflected in national legislation, it is critical that the revised national legislation be implemented effectively through appropriate administrative and judicial structures.

A chapter is said to be closed when both sides have agreed it has been implemented sufficiently, however it can still be re-opened if the Commission feels that the candidate has fallen out of compliance.

On 18 October 2019, France vetoed starting of negotiations with Albania and North Macedonia, citing problems with the current enlargement process.

[20] A later French President, François Mitterrand, opposed Greek, Spanish and Portuguese membership, fearing that the former dictatorships were not ready and that the countries' inclusion would reduce the union to a free-trade area.

[19] This has in particular been pushed by France and Germany as a privileged partnership for Turkey, membership for which has faced considerable opposition on cultural and logistical grounds.

[44] Half of the project states, Belgium, Luxembourg, and the Netherlands, had already achieved a great degree of integration amongst themselves with the organs of Benelux and earlier bilateral agreements.

[45] In 1962, Spain, ruled by the military dictator Francisco Franco, issued its first attempt to join the European Communities.

[20] Only after a 12-hour talk between British Prime Minister Edward Heath and French President Georges Pompidou took place did Britain's third application succeed.

[20] However François Mitterrand initially opposed their membership fearing they were not ready and it would water the community down to a free trade area.

[citation needed] Turkey received candidate status in 1999 and began full membership negotiations in 2005, which were still in progress as of 2021.

[51] Austria, Finland, and Sweden were neutral in the Cold War so membership of an organisation developing a common foreign and security policy would be incompatible with that.

The Community later became the European Union in 1993 by virtue of the Maastricht Treaty, and established standards for new entrants so their suitability could be judged.

The Copenhagen criteria stated in 1993 that a country must be a democracy, operate a free market, and be willing to adopt the entire body of EU law already agreed upon.

The EU struggled to deal with the sudden reunification of Germany with the addition of its poorer 17 million people and, while keeping its monetary union project on track, it was still at that early stage pointing the EFTA countries in the direction of the EEA rather than full membership.

Although eventually trying to limit the number of members, and after encouragement from the US, the EU pursued talks with ten countries and a change of mind[clarification needed] by Cyprus and Malta helped to offset slightly the influx of large poorer member states from Central and Eastern Europe.

These, like the countries joining in 2004, faced a series of restrictions as to their citizens not fully enjoying working rights on the territory of some of the older EU members until 2014.

The years subsequent to the EU accession will lead to extensive dialogues between policy-makers, governments, and European citizens about the path for a constructive development.

[72] The 2003 European Council summit in Thessaloniki set integration of the Western Balkans as a priority of EU expansion.

Albania and the several successor states of the Socialist Federal Republic of Yugoslavia have all adopted EU integration as an aim of foreign policy.

Accession negotiations are currently ongoing with Montenegro (since 2012), Serbia (since 2014), Albania (since 2020), North Macedonia (since 2020), Moldova (since 2024) and Ukraine (since 2024).

Negotiations with Turkey were opened in October 2005,[2] but have been effectively frozen by the EU since December 2016,[3][4][5] due to backsliding in the areas of democracy, rule of law, and fundamental rights.

[93] As of 2018[update], Kosovo was not recognised by fellow Western Balkan applicant Serbia and existing EU members Spain, Slovakia, Cyprus, Romania, and Greece.

[95][96][97] The European Parliament subsequently voted to accept an emergency petition from the government of Ukraine for EU member state candidacy.

These conditions included investing more in education and infrastructure and completing several reforms in elections, judicial independence, crime, corruption, and oligarchs.

[102] On 12 March 2024, the European Parliament passed a resolution confirming Armenia meets Maastricht Treaty Article 49 requirements and that the country may apply for EU membership.

[103] On 12 February 2025, the Armenian parliament approved a bill calling for the start of the process of Armenia's accession to the European Union.