The European Union does not need Serbia in the sentimental language often used around enlargement. It needs Serbia because geography, energy, industry and security have made the Western Balkans impossible to treat as a peripheral diplomatic file. Serbia is not merely another candidate country waiting in the corridor of Brussels bureaucracy. It is the largest economy in the Western Balkans, the central transport and energy junction between Central Europe and the south-east of the continent, and one of the few non-EU European states whose choices can materially affect the bloc’s supply-chain security, migration management, electricity-market integration and geopolitical exposure to China and Russia.
That does not mean Serbia holds Europe hostage. The EU is a 27-member economic and regulatory power with a market of more than 450mn people and a nominal GDP above €18tn. It can function without Serbia as a member state. But the more relevant question is not whether Europe collapses without Serbia. It is whether the EU can complete its strategic reordering of South-East Europe, secure critical corridors, reduce geopolitical leakage and build a credible enlargement policy while leaving Serbia in permanent ambiguity. On that question, the answer is increasingly uncomfortable for Brussels: no.
Serbia is the missing centre of the Western Balkans equation. Montenegro can advance quickly towards membership. Albania and North Macedonia can be folded deeper into the accession track. Bosnia and Herzegovina can be stabilised through institutional conditionality and external financing. Kosovo remains a political and legal challenge for five EU member states that do not recognise it. But without Serbia, the region remains structurally unfinished. Belgrade’s position touches almost every other file: Kosovo normalisation, Bosnia’s internal balance, Montenegro’s economic exposure, North Macedonia’s regional connectivity, energy flows, transport corridors and security co-operation.
For the EU, Serbia’s importance starts with geography. The country is the land bridge between Hungary, Romania, Bulgaria, Croatia, Bosnia and Herzegovina, Montenegro, North Macedonia and Kosovo. Road, rail, electricity and gas corridors pass through or around Serbian territory. A Europe increasingly concerned with military mobility, supply-chain resilience and infrastructure redundancy cannot afford to treat that space as a grey zone. The Danube corridor, the north-south logistics route towards Greece and Turkey, the east-west Balkan road and rail arteries, and the electricity interconnections linking Central Europe with the wider SEE market all make Serbia a strategic hinge rather than a diplomatic footnote.
This geography has become more valuable because the EU’s external environment has deteriorated. Russia’s war in Ukraine, the weaponisation of energy, the fragility of Black Sea logistics, the rise of Chinese industrial overcapacity and the renewed importance of hard infrastructure have changed the enlargement debate. In the 2000s, Brussels could speak of Western Balkan accession mainly in the language of reforms, reconciliation and democratic consolidation. In the 2020s, enlargement has also become a question of industrial security, energy systems, critical minerals, border control and strategic depth. Serbia sits directly inside that shift.
Economically, Serbia is already more integrated with the EU than its political debate suggests. The EU is Serbia’s dominant trade and investment partner, while Serbian manufacturers are deeply embedded in European supply chains across automotive components, machinery, metals, agri-food processing, packaging, ICT services and outsourced industrial production. German, Italian, Austrian, Slovenian, French and other European companies use Serbia as a nearshoring base, not just as a low-cost assembly platform but as a production location close to EU customers, ports and logistics networks. This gives Serbia a different profile from a distant third-country supplier. It is outside the EU legal order but increasingly inside the EU industrial perimeter.
That creates both opportunity and risk. For European manufacturers, Serbia offers labour availability, industrial zones, competitive operating costs and proximity to Central European production clusters. For Brussels, however, partial integration without full regulatory alignment creates a zone of dependence without complete governance. Public procurement, state aid, environmental permitting, labour standards, competition rules and judicial reliability all matter more when Serbian production feeds directly into the EU market. The deeper the economic relationship becomes, the more costly institutional ambiguity becomes.
The critical raw materials agenda has made this tension sharper. The EU–Serbia strategic partnership on sustainable raw materials, battery value chains and electric vehicles, signed in July 2024, turned Serbia into a visible test case for Europe’s attempt to reduce dependence on China in the green industrial transition. The Jadar lithium project, associated with Rio Tinto, sits at the centre of that debate. For Europe, Serbian lithium could support battery manufacturing, electric vehicle supply chains and the wider Critical Raw Materials Act logic of domestic and near-neighbour sourcing. For Serbia, it could bring investment, processing capacity, technology transfer and a more advanced industrial base.
Yet this is precisely where Serbia’s value to Europe collides with Serbia’s domestic vulnerabilities. Lithium is not just a mining project. It is a public trust project. Environmental concerns, water protection, land-use conflict, permitting credibility and local consent are not peripheral issues; they determine whether Serbia can become a serious European raw-materials partner or merely another contested extraction frontier. The EU cannot credibly present Serbia as part of its green transition while appearing indifferent to environmental governance. If Europe wants Serbian lithium, battery materials or industrial inputs, it must insist on the same bankable standards it demands from projects inside the Union: transparent permitting, independent monitoring, enforceable environmental safeguards and a credible social licence.
That makes Serbia a stress test for the EU’s new realism. Brussels wants strategic resources, but it also claims to represent regulatory quality. It wants to compete with China, but not by copying China’s tolerance for opaque infrastructure deals and weak consultation. It wants fast permitting, but cannot sacrifice public legitimacy. Serbia forces these contradictions into the open. The country could become a bridge between the EU’s industrial policy and Western Balkan development. It could also become evidence that Europe’s green transition is willing to outsource political and environmental risk to candidate countries.
Energy is the second decisive layer. Serbia is a coal-heavy electricity system with hydropower flexibility, emerging renewables, large grid-connection bottlenecks and growing pressure to modernise. For the EU, this matters because the region’s power markets are no longer isolated national systems. Cross-border electricity flows, balancing needs, carbon pricing, CBAM exposure, guarantees of origin, renewable PPAs and grid congestion are becoming linked across South-East Europe. Serbia’s transmission system and generation mix influence not only domestic prices but regional trading patterns with Hungary, Romania, Bulgaria, Croatia, Bosnia and Herzegovina, Montenegro and North Macedonia.
The EU’s Carbon Border Adjustment Mechanism will make this relationship more commercial and less abstract. Serbian exporters of steel, aluminium, cement, fertilisers, electricity and other covered goods will face growing pressure to document embedded emissions. Industrial buyers serving EU clients will increasingly need credible power-supply evidence, renewable procurement, metering data and plant-level emissions records. That means Serbia’s energy transition is not just a climate file. It is an export-competitiveness file. The more Serbian producers depend on EU markets, the more they will need electricity and carbon data that can survive EU scrutiny.
This gives Europe a strong interest in Serbia’s grid reform, renewable integration and market coupling. A Serbian system aligned with EU electricity rules would support regional liquidity, reduce balancing risks, improve price transparency and create bankable structures for renewables, storage and industrial PPAs. A Serbian system left in regulatory uncertainty would raise financing costs, slow renewable deployment and weaken the credibility of low-carbon exports into the EU. The question is not only whether Serbia builds more wind, solar, battery storage or pumped hydro. It is whether those assets are integrated into a market architecture that European banks, traders, offtakers and verifiers can trust.
Transport and logistics tell a similar story. Serbia is central to the EU’s effort to build resilient corridors across the Western Balkans. Rail modernisation, motorway links, Danube logistics, intermodal terminals and border-crossing efficiency all affect European companies using the region for production or transit. The EU has spent years trying to prevent infrastructure in the Balkans from becoming a competitive arena dominated by Chinese loans, Russian energy interests, Gulf capital or ad hoc bilateral politics. Serbia’s infrastructure choices therefore have a wider strategic meaning. A railway or motorway is not only a domestic project. It can become part of the EU connectivity space or part of a parallel geopolitical network.
This is where Brussels faces its hardest dilemma. Serbia’s government has mastered the politics of strategic ambiguity. It courts the EU as its largest economic partner, maintains ties with Russia, accepts Chinese infrastructure and industrial investment, cultivates relations with Turkey and the Gulf, and presents itself domestically as a state that does not fully belong to anyone’s orbit. This balancing has delivered leverage for Belgrade. But it has also slowed the trust needed for EU accession. The EU may need Serbia, but it does not need a Serbia that treats alignment as optional and reform as transactional.
The accession record reflects that tension. Serbia has been a candidate country since 2012 and opened accession negotiations in 2014. Yet progress has become uneven, with persistent concerns over rule of law, media freedom, corruption, public administration, foreign-policy alignment and the unresolved relationship with Kosovo. These are not bureaucratic irritants. They go to the heart of whether Serbia can be absorbed into the EU as a rules-based member state rather than as a strategic exception.
Kosovo remains the most politically sensitive obstacle. For the EU, normalisation between Belgrade and Pristina is not only a bilateral issue. It is a test of the Union’s ability to stabilise its own neighbourhood. For Serbia, Kosovo remains a defining domestic and constitutional question. For several EU member states, Kosovo’s status is also connected to their own internal concerns about separatism and recognition. This makes the file unusually complex. But the broader strategic point is clear: the EU cannot complete enlargement in the Western Balkans while the Serbia-Kosovo relationship remains a permanent security risk.
At the same time, Europe’s leverage is not as absolute as it once assumed. For years, the EU believed the promise of membership would be enough to drive reforms. That assumption has weakened. Enlargement fatigue inside the Union, slow accession timetables and inconsistent political messaging have reduced the credibility of the EU offer. Serbia’s leadership has used that vacuum to diversify partners and present Brussels as one option among several. The result is a relationship in which Serbia needs the EU economically, while the EU needs Serbia strategically, but neither side fully trusts the other’s long-term intentions.
This mutual dependence is the real architecture of the relationship. Serbia needs the EU because its exporters, investors, banks, workers and industrial base are tied to the European market. No alternative partner can replace the EU’s role in trade, capital, standards, labour mobility and long-term development. China can finance infrastructure and buy influence. Russia can supply political symbolism and energy links. Gulf capital can support selected real estate or logistics projects. But none can provide the full economic ecosystem that EU integration offers.
Europe needs Serbia for a different reason. It needs Serbia to close the geopolitical gap in the Western Balkans, prevent the region from becoming a marketplace of external influence, secure transport and energy corridors, and strengthen its industrial and raw-materials base. The EU’s strategic autonomy agenda remains incomplete if its immediate neighbourhood is fragmented. Serbia is too large, too connected and too central to be ignored.
The strongest European policy would therefore combine realism with discipline. Brussels should stop pretending that Serbia is just another slow-moving enlargement file. It should also stop treating strategic access as a substitute for democratic and regulatory reform. The EU’s interest is not in Serbia’s symbolic proximity but in Serbia’s institutional convergence. Trade, energy, lithium, transport and investment all become more valuable when they are governed by credible courts, predictable permits, transparent procurement and enforceable environmental standards.
For investors, this distinction matters. Serbia’s value proposition is real: industrial depth, competitive costs, location, skilled engineering capacity, EU market access, renewable potential, mining resources and logistics relevance. But the discount applied to Serbian opportunities is also real. Political concentration, regulatory unpredictability, permitting controversies, grid-connection uncertainty and geopolitical balancing all increase the cost of capital. Serbia can attract capital because it is strategically important. It will attract cheaper, longer-term and more sophisticated capital only if that strategic importance is converted into institutional reliability.
The same applies to the EU. Europe can use Serbia as a nearshoring base, a raw-materials partner and an energy corridor. But if it fails to anchor Serbia more firmly in its regulatory and political system, it risks building dependence on an unstable perimeter. That would reproduce one of the mistakes Europe is trying to escape: relying on strategically important external suppliers without sufficient control over governance, standards and resilience.
The Serbia question is therefore no longer whether the EU “wants” enlargement. It is whether the EU can afford strategic incompleteness in its own neighbourhood. Serbia is not ready to enter the Union without deeper reforms, and the EU is not ready to absorb Serbia without confidence that Belgrade’s alignment is durable. But the direction of travel matters. A Serbia moving gradually into the EU’s legal, energy, industrial and security architecture strengthens Europe. A Serbia left in permanent ambiguity weakens the Western Balkans, complicates the energy transition and leaves open a corridor for rival powers inside Europe’s own strategic backyard.
The EU does need Serbia. But it needs a Serbia that behaves less like a geopolitical swing state and more like a future member of a rules-based European system. Serbia needs the EU even more, but it needs an EU offer that is credible enough to make reform more rewarding than ambiguity. Between those two needs lies one of the most important unfinished bargains in Europe.
