More than 11 years have passed since Croatia became the then-28th member of the European Union in July of 2013, the last time the bloc expanded its borders. Since then, the EU has been consumed by a series of major crises, from debt and migration to Brexit and the COVID-19 pandemic, all of which put expansion firmly on the back burner. Russia’s invasion of Ukraine, however, has quickly propelled enlargement back to the top of the bloc’s agenda, with its leaders determined to convert the so-called “gray zone” between the EU and Russia into a bulwark against future Russian aggression.
Since the creation of the European Economic Community, or EEC, in 1957, a central tenet of the European project has been enlargement. The original bloc—comprising France, then-West Germany, Italy, Belgium, the Netherlands and Luxembourg—expanded westward in 1971 with the entry of the U.K. and Ireland; to the south in 1986 to incorporate the new democracies of Spain and Portugal; and northward, with the advent of the EU, into Scandinavia with the accession of Finland and Sweden in 1995. Earlier this year, the EU celebrated the 20th anniversary of its fifth and most significant enlargement, which saw seven former communist countries of Eastern Europe—Estonia, the Czech Republic, Latvia, Lithuania, Hungary, Poland and Slovakia—along with Slovenia and the islands of Malta and Cyprus, join the bloc. With the U.K. having withdrawn following the Brexit referendum, the other states rounding out the 27-member union are Greece, Austria, Bulgaria, Romania and Denmark.
Over the past two decades, a further 10 countries have signaled their ambition to become members of the club: the six western Balkan states of Albania, Bosnia and Herzegovina, Kosovo, Montenegro, North Macedonia and Serbia, along with Ukraine, Georgia, Turkey and Moldova. With the exception of Kosovo, all have attained “candidate country status,” which triggers a protracted process of negotiation toward eventual entry into the bloc.