Of all the countries queuing to join the European Union, one is not moving toward the door but away from it. Turkey, a formal candidate for more than a quarter of a century, is now the least-ready applicant in the field — and the only one whose readiness has gone backwards over the past five years.
That is the verdict of the Integration Readiness Index, a scoring system published by EPIC (readinessindex.eu) and co-produced with the Friedrich Naumann Foundation, whose authors — Antonios Nestoras, Emil Kirjas and Bernada Cunj — set out to measure how close each candidate actually is to membership using nothing but the EU's own paperwork.
The index scores ten candidate countries from zero to ten across the years 2021 to 2025, drawing exclusively on the European Commission's annual progress reports. It benchmarks each country against Croatia in 2011 — the last state to complete accession — and combines five measures: the current state of play, annual progress, how many Commission recommendations a country actually delivers, the status of its negotiating chapters, and its overall accession momentum.
The point of that method is discipline. Rather than lean on political mood or diplomatic flattery, the index turns Brussels' own assessments into a single number. For 2025, Turkey's number is 2.81.
The striking part is not just the low score but the direction. In 2021 Turkey scored 3.25 on the same scale. By 2025 it had fallen to 2.81. Every other candidate is, on balance, inching forward or holding; Turkey alone is regressing — the index's clearest example of a country drifting out of the EU's orbit.
The explanation is not economic weight, where Turkey dwarfs most of the field, but politics. Turkey's accession negotiations have been effectively frozen since 2018, when EU governments concluded that backsliding on democratic institutions, judicial independence and fundamental rights had brought the talks to a standstill. Nothing since has restarted them. In 2025 the European Parliament restated that Turkey's accession cannot resume under current circumstances, because the process requires the Union's core values to be fully respected. An index built from progress reports simply records, year after year, the absence of progress.
Turkey's 2.81 places it below every peer, including the two candidates usually described as the most troubled. Bosnia and Herzegovina, whose score collapsed from 4.14 in 2024 to 2.91 in 2025, still edges above it. Georgia, also sliding, sits at 3.26. At the other end, Montenegro (6.8) and Albania (6.7) lead the pack as genuine front-runners, while Ukraine and Moldova, both around 5.85, have overtaken long-standing Western Balkan candidates such as Serbia and North Macedonia, both on 5.5.
Measured against the Croatia-2011 benchmark, even the leaders have distance to cover. But they are travelling in the right direction. Turkey is the outlier that makes the index's larger point: candidate status is not a queue in which everyone advances simply by waiting. It is a measure of reform, and reform can go into reverse.
Turkey will not join the EU any time soon, and the readiness index explains, in cold arithmetic, why. But the finding matters beyond Ankara. It punctures the comfortable idea that enlargement is a one-way process — that a candidate, once accepted, is on an escalator to membership. The data show the escalator can run backwards. For the Western Balkans, for Ukraine and for Moldova, that is a warning as much as an encouragement: the door stays open only for as long as a country keeps walking toward it. For the EU, Turkey is the standing reminder that the most powerful tool of enlargement was never the promise of membership itself, but the reforms it was meant to pull into place — and that when those stall, no amount of strategic importance can move the number.
