by Marta Szpala
Executive Summary
The European Union’s enlargement policy has historically been its most successful foreign policy instrument, driving democratic transformation, economic convergence, and regional stability. The Russian invasion of Ukraine has acted as a geopolitical catalyst, ending a decade of “enlargement fatigue.” However, this newfound momentum creates a dangerous rift between the “lightning pace” of Ukraine/Moldova’s path and the “decade-long stagnation” of the Western Balkans. However, the current stagnation of the enlargement process—particularly in the Western Balkans and the Eastern neighbourhood—poses significant and multidimensional risks for the Union itself.
The European Union increasingly acknowledges enlargement as a geopolitical necessity, yet it remains deeply divided over how and when it should happen. While candidate countries are expected to undertake difficult reforms, member states continue to postpone strategic decisions about the future of enlargement, institutional reform, and the EU’s long-term geopolitical role. The result is a dangerous status quo: accession fatigue in candidate states, declining trust in the EU, growing influence of external actors, and a widening gap between political rhetoric and actual progress.
This policy paper argues that non-enlargement is not a neutral outcome but a strategically damaging scenario. This paper argues that the costs of non-enlargement are already visible and will continue to increase if the EU fails to act. A failure to enlarge would weaken the EU’s credibility, reduce its geopolitical leverage, undermine security in its neighbourhood, fuel anti-European narratives, and deepen internal fragmentation within the Union itself It contributes to geopolitical vacuum formation, increases susceptibility to external influence (notably from Russia and China), weakens EU credibility, exacerbates internal divisions, and undermines regional security architecture. Furthermore, it accelerates democratic backsliding in candidate countries, producing long-term instability that ultimately spills over into the EU.
At the same time, enlargement without strict conditionality would be equally damaging. Admitting countries that have not completed reforms—especially in the rule of law, judiciary independence, public administration, and anti-corruption—would risk importing new veto players and illiberal actors into the Union.
The paper identifies key consequences across geopolitical, security, economic, and societal domains and proposes a set of actionable policy recommendations. These include restoring credibility through a clear accession roadmap, deepening gradual integration, strengthening support for civil society, enhancing security cooperation, and maintaining strict rule-of-law conditionality. Without a renewed commitment to enlargement, the EU risks losing both its neighbourhood and its strategic relevance in an increasingly competitive global order
This paper is based on interviews conducted with 12 experts from EU member states in March and April 2026. The interviews explored the political, security, economic, and institutional implications of a failure to enlarge the EU. Experts were also asked to propose recommendations for avoiding such a scenario. The discussion focused both on the consequences for the EU as a whole and on the specific implications for the member states from which the experts originated.
1. Introduction
EU enlargement has long functioned as a cornerstone of European integration and external action. From Southern Europe in the 1980s to Central and Eastern Europe in the 2000s, enlargement has facilitated democratic consolidation, economic modernization, and the stabilization of post-conflict societies (Schimmelfennig & Sedelmeier 2005).
Today, however, the enlargement process faces unprecedented stagnation. Despite formal commitments to the Western Balkans and the granting of candidate status to countries such as Ukraine and Moldova, progress remains slow, fragmented, and politically contested. The gap between rhetorical commitment and practical delivery has widened significantly.
This disconnect risks transforming enlargement from a credible policy into a symbolic framework devoid of transformative capacity. As candidate countries lose faith in accession prospects, the EU’s ability to shape political and economic developments in its neighbourhood diminishes. The prolonged stagnation of the enlargement process is not a neutral state of “waiting”; it is a regressive process that generates systemic costs for both the candidate countries and the European Union. When the path to membership transforms into an “endless labyrinth” of procedural hurdles, the resulting vacuum is rapidly filled by instability and anti-democratic forces.
This paper explores the consequences of such a scenario. It argues that abandoning or indefinitely postponing enlargement will not only destabilize neighbouring regions but also generate direct and indirect costs for the EU. These costs manifest in weakened geopolitical influence, increased security vulnerabilities, economic inefficiencies, and internal fragmentation.
2. The Geopolitical Consequences of Non-Enlargement
2.1. Emergence of a Strategic Vacuum
A stalled enlargement process creates a geopolitical vacuum in the EU’s immediate neighbourhood. Historically, the prospect of EU membership has acted as a powerful anchor, aligning candidate countries with European norms and policies. Without this anchor, regions such as the Western Balkans and parts of the Eastern neighbourhood risk drifting into a “grey zone” of competing influences.
External actors—particularly Russia and China—are well-positioned to exploit this vacuum. Russia leverages historical, cultural, and energy ties to maintain political influence, while China expands its economic footprint through infrastructure investments and strategic projects under initiatives such as the Belt and Road (Hillman 2020).
This dynamic reflects what Farrell and Newman (2019) describe as “weaponized interdependence,” where economic networks are used for geopolitical leverage. In the absence of EU integration, candidate countries become more vulnerable to such practices, undermining both their sovereignty and the EU’s strategic interests.
2.2. Intensification of Great Power Competition
Non-enlargement transforms the EU’s neighbourhood into an arena of intensified geopolitical competition. Infrastructure development, energy supply, and digital networks increasingly become battlegrounds for influence.
For instance, large-scale projects such as railway corridors or energy pipelines are no longer purely economic ventures but strategic tools. Control over these assets allows external actors to shape political decisions, regulatory standards, and long-term dependencies.
Moreover, the EU’s reduced presence weakens its ability to set standards in areas such as environmental protection, labour rights, and digital governance. This creates regulatory fragmentation that benefits external powers while undermining the EU’s normative agenda.
2.3. Declining Global Credibility of the EU
The failure to deliver on enlargement commitments damages the EU’s credibility as a global actor. Enlargement has historically demonstrated the EU’s capacity to transform neighbouring countries through conditionality and incentives (Grabbe 2006).
When accession promises remain unfulfilled, this model loses legitimacy. Candidate countries begin to perceive the EU as unreliable, while external partners—including the United States—question its strategic coherence and capacity to act.
This credibility gap has broader implications. It signals internal divisions within the EU and suggests a lack of consensus on long-term strategic objectives. As a result, the EU’s influence in global governance frameworks and regional conflicts diminishes.
If the EU cannot stabilize and integrate its immediate geographical backyard, its claims to being a “global player” lose all credibility. This perceived weakness encourages external actors (Russia/China) to test the Union’s resolve more aggressively, not just in the neighborhood, but within Member States themselves.
The EU is a project built on values. When the Union fails to deliver on its promises to societies that have made enormous sacrifices for a “European future” (like Ukraine or North Macedonia), its soft power evaporates.
- Redundancy of the “European Model”: If the EU model is seen as “closed” or “exclusive,” it loses its appeal as a beacon for democratic reforms worldwide. This emboldens illiberal regimes within the EU to argue that democratic standards are optional, leading to a further erosion of the rule of law across the entire continent
2.4. The Cost of “Transactional Diplomacy”
As the EU’s transformative power diminishes, its relationship with the neighborhood becomes purely transactional. This forces the Union to constantly “outbid” rivals like Russia or the Gulf States to maintain basic stability, leading to an inefficient and expensive foreign policy that lacks long-term structural benefits. The shift toward transactionalism has transformed the enlargement process into a high-stakes financial negotiation. Instead of a merit-based proces, the relationship has evolved into a model where the EU must effectively “buy” the alignment of Balkan elites with its strategic initiatives.
In a transactional framework, Balkan leaders act as strategic brokers. They leverage their control over key issues—such as migration routes, energy transit, or regional stability—to extract financial concessions from the EU. The concept of weaponized interdependence (as defined by Farrell and Newman) is central to understanding this dynamic. The Western Balkan migration route is a prime example of weaponized interdependence. Local leaders understand that the EU’s internal stability depends on their border management. This creates a “reverse leverage” where the EU pays a high “protection fee” to avoid a political crisis at home, often turning a blind eye to domestic corruption in the region. While the EU uses its financial power to influence the Balkans, Balkan elites have learned to weaponize their own fragility. They signal that without continuous EU “investments,” their states might collapse, export instability, or fall entirely under the influence of rivals (China’s “debt-trap diplomacy” or Russia’s energy leverage).
3. Security Implications
3.1. Fragmented Security Architecture
The Western Balkans and Eastern neighbourhood are integral components of European security. However, without full integration, cooperation remains partial and insufficient.
Although candidate countries collaborate with EU agencies such as Frontex and Europol, this cooperation is limited by institutional constraints and lack of trust. Information sharing, joint operations, and strategic alignment remain incomplete, creating gaps in the EU’s security architecture.
In crisis situations—such as a sudden increase in migration flows—these gaps can become critical. Member states may resort to unilateral measures, undermining collective responses and exacerbating instability.
- The Trust Deficit: Law enforcement agencies do not share goals fully because there is no perception of a “shared future.”
- The “Every Man for Himself” Risk: In a future migrant crisis, without integration, the current architecture will collapse as each country relies solely on protecting its own territory, leading to regional deterioration.
3.2. Migration and Border Management Risks
Migration management illustrates the limitations of partial integration. While candidate countries play a key role in controlling migration routes, they do not fully share the EU’s objectives or capabilities.
Without full integration into the EU’s security architecture, the Western Balkan route remains a permanent vulnerability. Current cooperation with Frontex is transactional and fragile. In the event of a new major migration crisis, the lack of shared goals and trust would lead to a “save yourself” approach. Member states would likely reinstate internal borders (Schengen collapse), leading to the disintegration of one of the EU’s greatest achievements.
This creates a structural vulnerability: the EU depends on external partners for border control without having full oversight or alignment. In the event of a major migration crisis, this arrangement is likely to break down, leading to fragmented responses and increased pressure on EU borders.
3.3. Persistence of Hard Security Commitments
The EU continues to maintain security missions in regions such as Bosnia and Herzegovina and Kosovo. These missions require significant resources and limit the EU’s ability to respond to other global challenges.
Without enlargement, these commitments risk becoming permanent. Integration, by contrast, would allow for the internalization of security responsibilities and more efficient allocation of EU resources.
3.4. Hybrid Threats and Cybersecurity
The EU and its neighbourhood share a common security space, particularly in areas such as cybersecurity and disinformation. Non-enlargement weakens collective resilience against these threats.
External actors exploit governance weaknesses, media capture, and societal divisions to spread disinformation and undermine democratic institutions. Without deeper integration, the EU cannot effectively counter these threats at their source.
3.5. External Interference in Security:
External Interference in Security: A stagnant enlargement process allows strategic rivals to establish military and intelligence footprints in the region. This turns a potential “zone of peace and prosperity” into a “theatre of rivalry,” forcing the EU to spend significantly more on border defense and hybrid threat mitigation than it would have spent on the pre-accession process.
3.6. Importing Instability
A security vacuum in the neighborhood inevitably exports organized crime, human smuggling, and cyber threats into the heart of the Union. The cost of “policing” a hostile or unstable neighborhood far exceeds the cost of integrating it into a common law enforcement framework.
4. Economic and Environmental Costs
4.1. Missed Economic Opportunities
The Western Balkans and Eastern neighbourhood offer significant economic potential, particularly in the context of nearshoring and supply chain diversification.
Non-enlargement prevents the full integration of these markets into the EU economy, limiting growth opportunities and reducing economic resilience. It also increases the cost of maintaining stability through external funding mechanisms.
Lost Markets and Resources: While the EU hesitates, strategic rivals—primarily China—are securing long-term concessions in critical sectors such as rare earth minerals, energy infrastructure, and digital networks in the Balkans and the East. This creates a “leak” in the European Single Market’s influence, making the EU more dependent on supply chains controlled by revisionist powers.
Similarly, Enrico Letta’s report on the Future of the Single Market underscores that a larger EU remains the most effective tool to protect European interests and prosperity, uphold the rule of law, and defend EU citizens from external threats
4.2. Strategic Autonomy and Supply Chains
Enlargement is closely linked to the EU’s goal of strategic autonomy. Integrating neighbouring economies would strengthen supply chains and reduce dependence on external actors.
While the EU hesitates, strategic rivals—primarily China—are securing long-term concessions in critical sectors such as rare earth minerals, energy infrastructure, and digital networks in the Balkans and the East. This creates a “leak” in the European Single Market’s influence, making the EU more dependent on supply chains controlled by revisionist powers. Without enlargement, these regions may become integrated into alternative economic networks dominated by China or other powers, further weakening the EU’s position.
4.3. Environmental Externalities
Regulatory divergence in environmental standards creates cross-border risks. Peripheral regions may attract pollution-intensive industries, effectively becoming environmental “buffer zones.”
Issues such as water management, energy production, and pollution in shared ecosystems (e.g., the Adriatic Sea) require coordinated governance that is difficult to achieve without integration.
5. Internal EU Dynamics and Institutional Challenges
5.1. Deepening Internal Divisions
Enlargement debates increasingly reflect broader divisions within the EU. Member states differ on priorities, timelines, and conditionality, leading to policy paralysis. These divisions undermine the EU’s ability to act strategically and weaken its external credibility.
- Internal Political Cleavages: The “enlargement vs. treaty change” deadlock creates a paralyzing North-South and East-West divide. This internal friction prevents the EU from reaching consensus on other critical issues, such as defense spending or energy transition, as enlargement becomes a “hostage” to broader institutional disputes.
5.2. Enlargement Fatigue and Lack of Strategic Vision
The current approach to enlargement is characterized by short-term crisis management rather than long-term strategic planning. There is limited reflection on potential failure scenarios and their consequences.
This lack of strategic vision increases the risk of repeating past mistakes and failing to adapt to changing geopolitical realities.
Policy Recommendations
Non-enlargement is not a neutral scenario—it is a strategic risk with far-reaching consequences. A stalled enlargement process weakens the EU’s geopolitical position, undermines its security, and accelerates fragmentation both internally and externally.
A renewed commitment to enlargement—grounded in credibility, conditionality, and strategic vision—is essential for safeguarding the future of the European Union as a global actor.
Restore Credibility through a Structured Accession Process
The EU must provide clear, transparent, and time-bound accession pathways. This includes:
- Defining intermediate milestones
- Linking reforms to tangible benefits, Ensure consistent application of conditionality
- Improving communication with citizens in both member and candidate states
Credibility is the cornerstone of effective conditionality.
Strengthen Rule of Law Conditionality
Geopolitical urgency must not undermine core principles. The EU should:
- Maintain strict accession criteria Avoid political shortcuts
- Strengthen monitoring mechanisms, Ensure reforms are substantive and sustainable
- Ensure reversibility of benefits in case of backsliding
- This prevents the emergence of internal veto players that could weaken the Union from within, Prevent internal destabilization through premature accessio
Use Financial Leverage Strategically
- Expand pre-accession funding
- Link financial support to concrete reform outcomes
- Invest in infrastructure and green transition
Strategic Communication
For enlargement to succeed, EU leaders must move beyond technocratic language and engage in a sincere, transparent dialogue with their own societies. The lack of a clear narrative has allowed skepticism to grow, particularly regarding the perceived competition between the “new” candidates (Ukraine and Moldova) and the Western Balkans. EU leaders must communicate that the enlargement process is not a “zero-sum game.” Strategic communication cannot be limited to Brussels summits. It must reach the ” citizens in both the current Member States and candidate countries.
The EU must be clear that while the opportunity is geopolitical, the entry remains strictly merit-based. This “tough love” narrative helps reassure EU citizens that standards of rule of law and corruption-fighting will not be lowered for the sake of speed.
Strengthen Democratic Resilience
- Increase funding for civil society and independent media
- Build transnational democratic networks
- Counter disinformation and foreign interference
Enhance Security Integration
Deepen cooperation in border management and law enforcement
- Integrate candidate countries into cybersecurity frameworks
- Develop joint responses to hybrid threats
Invest in Youth and Future Leadership
- Expand educational and mobility programmes
- Support emerging pro-European leaders
- Encourage youth participation in governance
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The paper authored by Szpala on this topic is part of a project implemented by the Albanian Institute for international Studies (AIIS) and supported by a grant from Open Society Institute – Sofia Foundation (OSIS) with the support of Open Society Foundations (OSFs).
