The Expanding Union: Stability and Growth at Europe’s Edges

Tuesday 10 March 2026

For much of its history the European Union has advanced less through grand constitutional leaps than through steady territorial expansion. Each enlargement round has carried political risk, economic uncertainty and cultural anxiety; yet, taken as a whole, enlargement has proved to be the Union’s most reliable instrument for exporting stability, prosperity and democratic norms. As the European Union contemplates the accession of Ukraine alongside the remaining Balkan states still outside its institutional framework, the question is not merely whether expansion can continue, but whether it can continue to deliver the political stabilisation and economic growth that have long justified it.

The optimistic case is stronger than it may first appear.

Enlargement as a stabilising technology

The European Union has rarely functioned as a coercive power; rather it has excelled as a regulatory and aspirational one. The accession process itself has historically been the Union’s most effective stabilisation mechanism. Candidate states are required to undertake deep reforms in governance, judicial independence, market regulation and minority rights, not as abstract ideals but as practical prerequisites for membership. This conditionality has repeatedly anchored fragile political systems to a predictable reform trajectory.

The experience of Central and Eastern Europe after 2004 demonstrated this effect vividly. Countries emerging from post-socialist uncertainty were drawn into a dense web of legal obligations, investment flows and institutional habits that made political backsliding materially more difficult. While democratic erosion has occurred in certain member states, it has unfolded within a framework that still constrains outright authoritarianism and preserves economic integration.

The Balkans present a similar opportunity. The unresolved legacies of Yugoslavia, weak institutions and ethnic tension have long made the region vulnerable to stagnation and external influence. Yet the prospect of European Union membership continues to function as a powerful disciplining force. Even when progress is slow or politically contested, the accession framework offers a shared destination that moderates extremes and incentivises compromise.

Ukraine and the geopolitics of belonging

Ukraine’s candidacy carries a different though complementary logic. Her pursuit of membership is inseparable from the war imposed upon her by Russia. Yet it would be a mistake to see Ukrainian accession solely as a geopolitical gesture. The reform momentum generated since 2014, and accelerated during wartime, aligns closely with the European Union’s long-standing enlargement methodology.

For Ukraine accession represents not only security anchoring but economic transformation. Integration into the single market promises access to capital, technology transfer and labour mobility at a scale no bilateral arrangement could replicate. For the European Union, Ukrainian membership would extend the Union’s regulatory and economic space eastwards, strengthening supply chains in agriculture, energy and industrial production.

Crucially enlargement here is not an act of charity. Ukraine’s population, human capital and industrial capacity offer long-term growth potential to an ageing Union. As with earlier enlargements, short-term adjustment costs are likely to be offset by long-term gains in productivity and market depth.

Economic growth through integration, not isolation

Critics of enlargement often frame it as a fiscal burden. Structural funds, agricultural subsidies and cohesion spending do require redistribution. Yet the historical record suggests that enlargement has consistently expanded the Union’s overall economic base. New member states become export markets, investment destinations and sources of labour that sustain growth across the bloc.

The Balkan economies, although small individually, sit at the crossroads of European transport, energy and digital corridors. Their integration would reduce transaction costs, improve regulatory coherence and attract investment that currently hesitates in the face of political risk. For investors, accession transforms uncertainty into calculable risk, which is often the decisive threshold for long-term capital.

Moreover enlargement strengthens the European Union’s capacity to act collectively in an increasingly fragmented global economy. Larger internal markets are more resilient to external shocks, more attractive to global partners and better positioned to set regulatory standards rather than merely adopt them.

Political maturity through expansion

There is also a subtler, often overlooked, benefit to enlargement: it forces the European Union herself to mature politically. Each expansion has compelled institutional adaptation, from voting rules to budgetary frameworks. While this process is frequently uncomfortable, it has historically driven innovation rather than paralysis.

The inclusion of Ukraine and the remaining Balkan candidates would oblige the Union to confront questions of governance, solidarity and strategic purpose with renewed seriousness. Far from weakening the European project, this may sharpen it. A Union confident enough to expand is one that still believes in her own future.

A cautiously optimistic horizon

None of this suggests that enlargement will be easy. Institutional reform within the European Union, credible enforcement of rule-of-law standards and careful sequencing of accession will be essential. Yet the alternative – a Europe that retreats from expansion – carries its own risks: unstable neighbours, lost economic opportunity and a gradual erosion of normative influence.

The European Union was not built as a closed club, but as an evolving political and economic space. Its most successful periods have coincided with moments when she chose openness over hesitation. In that historical light, continued expansion – embracing Ukraine and completing the long-delayed integration of the Balkans – remains one of the Union’s most promising tools for generating stability and growth, both at her borders and within them.

Optimism in this context is not naïveté. It is an evidence-based confidence grounded in the European Union’s own experience – and in her enduring capacity to transform aspiration into durable political reality.