EU enlargement: the institutional trap no one will name
The EU's official position is that enlargement is a strategic priority.
Its own documents reveal a structural impossibility that neither the Commission nor member states are willing to put on the table.
At a Glance
The EU currently has nine official candidate countries. None are in a position to join before 2030 at the earliest — and the Union’s existing rules were not designed to absorb ten additional members without deep prior reform.
The budgetary cost of admitting Ukraine alone would require a massive restructuring of the Common Agricultural Policy and cohesion funds — a reality documented by independent economic institutes that politicians who publicly support enlargement carefully avoid quantifying.
The 2004 enlargement is routinely cited as the successful precedent validating the method. Internal institutional evaluations tell a more nuanced story — one whose lessons have not been incorporated into the current enlargement cycle.
This image is used for illustrative purposes only.
What the official process actually covers
The European Union — the EU, the 27-nation bloc that functions as both a single market and a shared governance system — currently has nine official candidate countries: Ukraine, Moldova, Georgia, Albania, Bosnia-Herzegovina, North Macedonia, Montenegro, Serbia, and Turkey. Kosovo holds the status of potential candidate.
For each of them, the process is governed by the Copenhagen criteria, established in 1993: a functioning democracy with the rule of law, a viable market economy, and the capacity to absorb the entire body of EU law — tens of thousands of pages of regulations, directives, and decisions that make up the acquis communautaire.
The Commission’s annual Enlargement Package evaluates each candidate against these three dimensions, chapter by chapter. Reading these reports is instructive — not for what they confirm, but for what they measure. For most of the Western Balkans, accession negotiations have been open for more than a decade: Montenegro since 2012, Serbia since 2014. Successive reports document genuine progress on technical chapters — public procurement, industrial standards, taxation — alongside persistent stagnation on the fundamental chapters: rule of law, judicial independence, anti-corruption. This is not a scheduling accident. It reflects a structural tension between the legal alignment required for membership and the domestic political equilibria of governments whose model of power depends precisely on the practices the EU demands they dismantle.
For Ukraine and Moldova, negotiations opened in June 2024, with the technical screening process now largely completed. It was a politically significant decision taken in the context of the war, carrying legitimate value as a strategic signal. But opening negotiations is a technical procedure distinct from accession: it means the process of formal alignment with EU law begins. In Ukraine’s case — a country of 44 million with one of Europe’s largest agricultural economies — that process is of unprecedented complexity, and it is unfolding during wartime, with significant portions of the country’s territory and administration outside government control. For comparison: Turkey has been an official EU candidate since 1987 and opened accession negotiations in 2005. It is still a candidate.
The arithmetic problem nobody wants to solve
The European Union at 27 operates under rules designed, in their fundamental architecture, for a much smaller organization. The unanimity rule in the Council of the EU — maintained for tax, constitutional, and foreign policy decisions — gives every member state an effective veto. In a Union of 35 or 37 members, this mechanism would make decision-making even more laborious than it already is. And it is already regularly paralyzed.
The composition of the European Commission — the EU’s executive arm, roughly equivalent to a federal cabinet — illustrates the tension. The Treaty of Lisbon, the 2007 reform treaty that serves as the EU’s current constitutional foundation, originally envisioned reducing the number of commissioners below one per member state. A commission of 27 is already unwieldy; distributing portfolios becomes an exercise in diplomatic balancing rather than functional governance. That reduction was never implemented. With ten additional members, a Commission of 37 would become an institutional object whose internal governance becomes a permanent challenge in itself.
In the European Parliament — the EU’s directly elected legislative body — the equation is similar. The treaty sets a ceiling of 751 MEPs. Integrating nine new member states requires either a treaty revision to raise that ceiling or a reduction in the representation of existing members — a politically costly negotiation that no one wants to open before knowing how many additional members must eventually be accommodated.
The institutional reform that is a precondition for any significant enlargement itself requires unanimity among existing member states. That is: the states whose representation and influence would be mechanically reduced by that reform must approve it. The circle closes before it has been opened.
The budget calculation capitals prefer to avoid
Economic estimates of the budgetary impact of enlargement to Ukraine are known to institutions and systematically absent from public political debate. Several independent economic institutes have modeled what Ukrainian accession would mean for the EU budget. Ukraine is a major agricultural country: its usable agricultural land area exceeds that of France. Under the current Common Agricultural Policy framework, Ukraine would immediately become the largest recipient of direct payments to farmers — ahead of France, Germany, and Poland combined, according to some models.
The EU’s multiannual financial framework — its seven-year budget — is negotiated among member states according to a carefully calibrated balance of net contributions and net benefits. Integrating Ukraine into this framework without fundamentally revising the distribution parameters would transform several currently net-recipient states — including some members that joined in 2004, such as Poland — into net contributors. This redistribution, which touches the most concrete domestic interests of every government involved, is politically unthinkable without a wholesale renegotiation of the budget. That renegotiation, in turn, requires unanimity.
This is not a case of governments being unaware of the reality. They have a collective interest in not making it public for as long as membership remains a distant horizon. Pro-enlargement rhetoric is cheap when the deadline is undefined. The political cost of budgetary honesty would be immediate.
What the 2004 assessment actually says
The 2004 enlargement — the simultaneous accession of ten new member states, eight of them former communist-bloc countries — is presented in official EU discourse as the flagship success of the integration method. It is the precedent systematically invoked to demonstrate that enlargement works.
Institutional evaluations offer a more nuanced account. The European Court of Auditors — the EU’s independent financial watchdog — has published multiple audit reports on the use of pre-accession funds and cohesion funds in states that joined the EU since 2004. Those reports document absorption rates for structural funds that fell significantly below targets in the early years, administrative capacity in several new member states insufficient to manage EU programs, and anti-fraud control recommendations that took years to be partially implemented.
This track record does not invalidate the 2004 enlargement, which contributed to genuine economic modernization and democratic consolidation in several countries. But it raises a question that current pro-enlargement discourse does not address: do today’s candidate countries present administrative, judicial, and institutional capacities comparable to those of the states integrated in 2004 — which themselves had documented weaknesses? For the Western Balkans, whose negotiations have been stuck on rule-of-law chapters for ten years, the answer the Commission’s own progress reports suggest is clearly no. For Ukraine, whose administration is operating under wartime conditions, the question cannot be posed in peacetime terms at all.
Why this extends well beyond Europe
The European dilemma between enlargement and institutional reform is not specific to the EU. It is the fundamental problem of any international organization confronted with its own growth: how to integrate new members without diluting the decision-making capacity of the whole, and without existing founding members losing the proportional influence that justified their original investment.
NATO, the transatlantic military alliance, has managed this tension through a less integrated architecture: membership entails mutual defense obligations and military interoperability, but not shared economic governance or a transfer of regulatory sovereignty. The cost of integrating a new member is fundamentally different in nature — which is one reason NATO’s enlargement, while politically contested, has not produced the same institutional paralysis as the EU’s.
For an American reader, the most illuminating analogy may be constitutional rather than military. The debate that ran through the United States between 1787 and the 1850s over the admission of new states into the Union posed the same fundamental questions: how to preserve the balance of power among existing members when new states arrive and alter the equilibrium in the Senate, the House, and the Electoral College? The American solution was to negotiate case by case, state by state, with compromises that sometimes carried very high costs — including, ultimately, a civil war over the question of slavery in new territories.
The EU is looking for a cleaner solution. It has not found one.
Analysis
A tension twenty-five years in the making
The question “should the EU reform before it enlarges?” did not emerge with Ukraine’s membership application in 2022. It has structured the European institutional debate since the Treaty of Nice, signed in December 2000, one of whose explicit purposes was to prepare the institutions for the enlargement then imminent. Nice produced limited technical adjustments — vote reweighting in the Council, Commission recomposition — without resolving the underlying question. The Convention on the Future of Europe (2002-2003) attempted an ambitious answer through the Constitutional Treaty, rejected by French and Dutch referenda in 2005. The Treaty of Lisbon (2007) salvaged some of its provisions in a less politically visible form. Since then, the institutional question has been officially open — and officially non-urgent.
Who is actually blocking, and why
The standard media narrative identifies Viktor Orbán, Hungary’s prime minister, as the primary obstacle to enlargement — particularly regarding Ukraine. This framing is partially accurate and mostly misleading. Orbán blocks for reasons specific to his own position (relations with Moscow, specific economic interests, domestic political calculus); his veto on Ukraine’s accession negotiations has prompted the European Council to explore moving accession cluster votes to qualified majority rather than unanimity — a procedural workaround that illustrates both the urgency and the limits of the current framework. But the governments presenting themselves as the most ardent champions of enlargement — France, Germany, the Nordic countries — are precisely those whose budgetary and institutional interests would be most affected by a genuine prior reform. Their declared support for enlargement coexists with structural resistance to any reform of the CAP or Council voting rules that would be the necessary precondition for that enlargement. This is not calculated hypocrisy — it is the normal logic of actors maximizing their interests in a medium-term horizon, while genuine enlargement remains a long-term one.
The ratification trap
There is a second layer to this paralysis that rarely enters the institutional conversation: even if the Council clears the way and negotiations conclude, every accession treaty must be ratified — unanimously — by all existing member states, through parliamentary votes or referenda. A Special Eurobarometer survey conducted in early 2025, covering over 26,300 citizens across all 27 member states, found that 56% of EU citizens support further enlargement — a majority, but a thin one, and unevenly distributed. Support reaches 79% in Sweden and 75% in Denmark, but falls to just 43% in France and the Czech Republic, and 45% in Austria. The concerns driving that skepticism are concrete: 40% of respondents cite uncontrolled immigration, 39% corruption and crime, and 37% the financial cost to taxpayers. These are precisely the arguments that sovereignist and nationalist parties — now present in governing coalitions across the EU — have proved most effective at amplifying. Croatia’s accession treaty took 18 months to ratify in 2012, in a Union that was then less fragmented. The next ratification round will unfold in a political landscape where any government facing a tight parliamentary majority or an upcoming election has every incentive to stall, hedge, or demand side-payments before signing. The unanimity trap is not only upstream, in the Council chambers where vetoes are cast. It is also downstream, in every national parliament that will eventually be asked to say yes.
The workarounds that reveal the trap
The depth of the impasse is most visible in the solutions being proposed to escape it. In 2025-2026, the European Commission floated a concept variously called “reverse enlargement” or “phased integration” — admitting Ukraine formally first, then conditioning full access to single-market rights and voting privileges on meeting reform criteria afterward. The proposal was rejected by EU ambassadors in March 2026, who asked the Commission to find a more realistic path forward. Meanwhile, a separate proposal circulated to strip new members of veto rights for a transitional period after accession — a frank admission that the unanimity rule cannot survive enlargement, paired with an unwillingness to reform it for existing members. Both proposals share the same logic: find a way to enlarge without actually resolving the institutional question. That both were rejected or stalled confirms what the documents have long shown — the trap is structural, not diplomatic.
Two frontrunners, and what they reveal
Not all candidates are equal. Montenegro and Albania have emerged as the genuine frontrunners: Montenegro has closed four negotiating chapters over the last year and has set a target to conclude negotiations by end-2026, with EU member states having proposed in December 2025 to begin drafting its accession treaty. Albania aims to conclude negotiations by 2027. These two smaller, less economically disruptive candidates could, in theory, reach the finish line by 2028-2030 under the current model — and their potential accession is significant precisely because it would be the first test of whether the ratification process can still function in a more fragmented and polarized Union than existed when Croatia joined in 2013. Montenegro and Albania, in other words, are not just frontrunners — they are the canary in the coal mine for every candidate that follows.
The Bottom Line
The European Union is promising membership to nine candidate countries. It is not saying when. It is not saying under what institutional and budgetary conditions. It is not saying who will pay. And the documents that would allow those questions to be answered exist — published by its own institutions, in its own archives.
The real question this dossier leaves open is not whether the EU will enlarge — it will, the geopolitical logic demands it. The real question is: at what institutional price, and who will be in a position to make whom pay it? Because this is ultimately a redistribution game — of influence and resources between current and future member states — and that game has not yet begun to be played openly.
Sources: European Commission — Enlargement Package 2025 · European Court of Auditors — audit reports on pre-accession funds · Bruegel — economic analysis on enlargement costs · Eurostat · European Council — December 2023 summit conclusions · EUR-Lex — Article 49 TEU · European Council on Foreign Relations (ECFR) · DGAP/Clingendael — “Europe’s Next Enlargement” (May 2026) · EU Institute for Security Studies · Special Eurobarometer 564 — Attitudes towards EU Enlargement (European Commission, September 2025)