Turkey applied to join the European Economic Community 30 years ago. In 1997, the bloc declared it eligible to join the EU and in 2005 accession talks began. But now, years of painstaking negotiations could collapse altogether.
EU members are mulling either suspending or ending the talks – which were put on ice in November 2016 – in light of Turkish government policies under President Recep Tayyip Erdogan that have eroded the rule of law and human rights.
Although openness toward Turkey as an EU member state varies by country, no nation in the bloc favors unconditional accession for Ankara.
Against full EU membership for Turkey
Chancellor Angela Merkel has called on EU member states to consider ending – or at least suspending – accession talks with Turkey.
The proposal follows the arrest of a number of German citizens in Turkey, as well as a call by President Erdogan for German-Turks to vote against Merkel in the upcoming general elections.
In the past, Germany's conservative parties have advocated for a privileged partnership, rather than full membership. By contrast, Merkel's center-left coalition partner, the Social Democrats (SPD), have remained open to negotiations with Turkey. SPD candidate Martin Schulz surprised German voters, however, when he went sided with Merkel during a live TV debate in early September.
Diplomatic relations are rocky between the two countries, but the partnership remains a vital one both for security and political interests: Roughly 3 million residents in Germany are from Turkey or have Turkish roots.
In 2016, the Austrian government led calls for the EU to end talks with Turkey and maintains this stance today.
Citing mass arrests in the wake of Turkey's failed coup, Austrian Chancellor Christian Kern said democratic standards in Ankara were "clearly not sufficient to justify accession."
Although past Belgian governments have favored Turkish EU membership, Prime Minister Charles Michel changed this stance in March when he called for an end to the negotiations.
Pointing to Erdogan's departure from European values, Michel stressed that diplomatic relations were deteriorating swiftly under the autocratic president.
Some countries remain on the fence
Paris's attitude toward Ankara has shifted in recent years, with President Nicolas Sarkozy staunchly opposed to Turkey's accession to the EU. Relations later stabilized under Francois Hollande. France's newest president, Emmanuel Macron, has yet to reveal what his government's official position is.
The issue of expanding the EU to include the Muslim country has not received much attention in public debate, perhaps due to the unlikelihood of its taking place any time soon.
Luxembourg and Denmark
The tiny EU member state of Luxembourg supports maintaining dialogue with Turkey, but has been neither strongly supportive of nor opposed to its inclusion into the bloc. Like many of its neighbors, Luxembourg has voiced concerns about Turkey drifting away from the values and principles that unite EU member states.
Denmark has maintained a pragmatic approach toward Ankara without strongly supporting or opposing negotiations.
With its own days as an EU member state marked, the UK's diplomatic relations are currently in flux.
The British government has historically been open to Turkey joining the EU. However, euroskeptic party UKIP exploited immigration fears by arguing, among other things, that a Turkish EU member state would open the doors to Muslim immigrants.
Member states that favor Turkish accession
Ireland supports Turkish accession in theory, but has stressed that Turkey must show its commitment to EU values.
Italy, Malta, Spain and Portugal
These Mediterranean neighbors have remained committed to allows talks to move forward.
While Portugal generally supports giving other countries a chance to benefit from EU membership as it did, Spain sees a close relationship between Brussels and Ankara as key for geopolitical stability in the region. Italy, meanwhile, is Turkey's third most important EU trade partner.
As these countries see it, halting talks would not only be counterproductive, but would also be difficult to resuscitate if the EU changes its mind.
Finland and Sweden
The two Nordic countries have backed negotiations with Turkey, with the Finnish government the more openly supportive of the two.
Both have raised concerns in recent years as the rule of law deteriorates in Turkey. Neither Finland nor Sweden view membership for Turkey as unconditional.
Estonia, Latvia and Lithuania
Estonia, Latvia and Lithuania are loathe to criticize President Erdogan: Turkey has been a strong security and defense partner to the three countries since their accession to NATO in 2004.
They see Ankara as a good long-term partner for the EU. However, like other young EU member states, "fair is fair." Turkey must play by the same rules as everyone else.
Poland, the Czech Republic, Slovakia, Hungary, Romania and Bulgaria
Security in Eastern Europe and relations with Russia dominate foreign policy among these EU member states. Regarding Turkey, the views range from disinterest to strong support.
In Poland and the Czech Republic, for example, there is little public debate about Turkish accession to the 28-member bloc. By contrast, Romania – whom Turkey backed for accession to NATO in 2004 – voiced its support for Ankara before it even joined the EU.
Croatia and Slovenia
While Slovenia has shown little concern over Turkey, Croatia has remained cautious toward expressing its opinion. Like Turkey, its accession talks began in 2005. Twelve years later, however, it enjoys full EU membership, while Turkey's status has stalled.
Both countries are open to Turkish membership provided Ankara meet the requirements.
Greece and Cyprus
Greece and Cyprus support Turkish accession, but not unconditionally.
Given past tensions with the Middle East neighbor, both EU member states see Turkey joining the bloc as a positive development that could sway Ankara toward maintaining peaceful relations.
However, the two countries remain wary of Ankara in the wake of the failed coup attempt in 2016. Greece, for its part, faced threats from Erdogan over its refusal to extradite a group of Turkish officers wanted in connection with the incident.