Stumbling blocs: Why the EU’s future security depends on successful enlargement

At this year’s Munich Security Conference, US vice president J.D. Vance asserted that Europe faces more threats from within than it does threats from China and Russia. He was correct, but perhaps not in the way he meant. Vance and his Trump administration colleagues—who have made no secret of their “loathing” for Europe—are not likely to hesitate to help undermine the EU internally by collaborating with far-right figures in Europe.

Then, in March 2025, just one month after Vance’s speech, the Mathias Corvinus Collegium and the Ordo Iurius Institute drafted a report with suggestions on how to revamp the EU. Both organisations are so-called governmental NGOs, and enjoy backing from Hungary’s right-wing government and the Polish right-wing political movement, respectively. They launched “The Great Reset”—which calls for a stronger EU based on “member-state interest”, reducing the power of the commission, extending unanimity, limiting the authority of European Court of Justice (CJEU), and renaming the EU as “the European Community of Nations”—at the Heritage Foundation in Washington.  

For its part, the Heritage Foundation, a right-wing American think-tank with ties to the Trump administration, is actively pursuing deeper relations with likeminded politicians in Europe. As Vance foretold—and with global geopolitical developments amplified by Russia’s continued aggression against Ukraine and Vladimir Putin’s close relationship with China—the threat to European sovereignty is no longer contained outside EU borders.

It is time for EU institutions and member-state leaders to consolidate the European geopolitical space by urgently moving ahead with the next phase of EU enlargement. If successful, the bloc will be better able to defend itself—both inside and out.    

Strengthening collective security

Russia and China’s developing strategic partnership is further complicating Europe’s security challenges; the stronger it becomes, the more potentially detrimental the partnership could be to Europe’s economic growth, freedom, and unity. The geopolitics tied up with Xi Jinping and Putin’s tacit understanding that Chinese interests depend on Xi’s support for the Russian regime and its aggression in Ukraine is becoming clear at the domestic level, too.

A recent ECFR publication demonstrates that both Chinese and Russian citizens understand the relationship between the countries to be that of an allyship based on “shared interests and values”, and not only one based on strategic necessity. 

Although China is expanding its influence in several EU candidate countries, their publics remain generally pro-European—including in Serbia, whose Russian-sympathetic government also recently signed a free trade agreement with China. Ostensibly, however, most EU candidate countries want more Europe and less Russia: the enlargement process is deeply intertwined with security imperatives, particularly with future US support for European defence and NATO so uncertain. Integrating candidate countries like Moldova, Ukraine and the Western Balkan states into the EU framework is now a clear strategic necessity.

EU enlargement allows the bloc to better strengthen its collective security, stabilise peripheral volatile regions and enhance its resilience against external threats

European Commission president Ursula von der Leyen has reiterated her commitment to enlargement multiple times since she received the backing of the EU parliament for her second mandate. EU enlargement allows the bloc to better strengthen its collective security, stabilise peripheral volatile regions and enhance its resilience against external threats. But von der Leyen also needs political backing from EU member states for enlargement to be a success.

Enlargement also requires high levels of political will, and a sustained commitment from EU and member state leaders. Now the EU should consider taking three important steps to facilitate a smoother accession process.

1. Suspend Hungary’s voting right

The EU’s biggest obstacles to developing effective foreign and security policy are disagreement on objectives among member states and inefficiencies of the decision-making process. This is being exacerbated by rogue actors, such as Hungary’s far-right prime minister Viktor Orban: he is consistently trying to undermine the EU’s democratic function by vetoing Ukraine’s accession process and previously threatened the same action against Russian sanctions (despite eventually voting to maintain them in all 16 rounds). As it stands, even if the EU’s 26 member states achieve cross-party agreement on how to respond to, for example, the tariffs imposed by the Trump administration, or on how to help Ukraine achieve victory against Russia, it only takes one Orban to paralyse the EU’s course.

It is therefore in the interest of EU enlargement that the re-energised “Weimar Triangle”—a loose coalition comprised of France, Germany and Poland ( strengthened since end of 2023 by an addition of left-of-centre prime minister Donald Tusk)—collaborates to drive the process of calling for Article 7 of the Treaty of the European Union (TEU). This would suspend Hungary’s voting right in the European Council, at least temporarily or until Orban is no longer the prime minister.

But the Weimar Triangle cannot act alone: they need support from member states, which can only be achieved through close collaboration, aligned perspectives and persuading others to jump on board. This can be done. France was traditionally sceptical about EU enlargement but has—since Russia’s invasion of Ukraine in February 2022—voiced its support for both EU enlargement and, specifically, Ukraine joining the EU. For France and its president Emmanuel Macron, a consolidated, peaceful Ukraine is imperative for a secure European future.

Similarly, likely next German chancellor Friedrich Merz has called for the Weimar Triangle to take an active role on the European stage in order to shape EU policy. He, along with the incoming German government, is also pressing the EU to “hold funds and suspend voting rights to obstructive countries”. For Germany, enlargement is a strategic interest because it promotes stability and democracy in neighbouring countries: it is staunchly for integrating the Western Balkans into the EU, recognising how membership can help resolve long-standing ethnic conflict and reduce external, nefarious influences from China and Russia.

2. Establish qualified majority voting on enlargement

Whether the EU successfully manages its next phase of enlargement also hinges on it carrying out reforms to improve functionality and increase its decision-making efficiency. The EU needs to work more effectively now to let more members in; then retain this efficiency once the union has actually expanded. Institutional reforms must therefore balance how ready the EU is for enlargement with geopolitical realities, which are increasing the urgency of the situation.

To streamline enlargement decisions, there is growing support among EU member state representatives for the use of qualified majority voting (QMV) instead of unanimity. A recent co-authored German-Slovenian “non-paper” on introducing QMV on enlargement calls for its use when opening and closing clusters and chapters, to simplify and speed up the accession process for candidate countries.

While the TEU is explicit over national applications to join the EU, as laid out in Article 49, it is not explicit about unanimity over the entire enlargement process: so far, member states have decided each step in the enlargement process via unanimity. But this provides opportunity to block bids from individual candidate countries for more nationalistic reasons—for example, Bulgaria’s cultural opposition to the accession of North Macedonia and Greece’s potential to block Albania over what it considers the latter’s lack of respect for its ethnic Greek minority. The same is true for Hungary’s blocking of Ukraine’s accession on minority issues and geopolitical grounds.

Legally there are no obstacles to adopting QMV when opening and closing clusters and chapters during the accession process; the shift would merely prevent individual member states from vetoing decisions. But even if the popularity of QMV rises, the EU still needs to ensure that such institutional reforms go hand-in-hand with its enlargement timeline, so that it does not leave the issue of expansion on the back burner. While some member states, such as the Netherlands, argue that reforms should precede further expansion, many others maintain that reforms and enlargement can progress in parallel without delaying accession for candidate countries.

3. Grant Ukraine and Moldova associate member status

In December 2023, EU member states agreed to put Ukraine and Moldova on an EU integration path to accession. In the meantime, EU associate membership for Ukraine and Moldova would allow both countries to integrate into the single market, become part of the CJEU, and perhaps participate in EU’s security and defence programmes and initiatives. The countries would have the chance to align their legislation with the EU common law and obligations, and prepare for full membership.

However, member states are divided over the speed and rigidity of the accession process. Countries like Poland, and those in the Baltics and the Nordics, view enlargement as a necessary geopolitical response to Russian aggression. They emphasise that rapid integration—especially for Ukraine and Moldova—will strengthen overall EU security, secure Europe’s eastern borders and reinforce democratic governance in the candidate countries. In March 2025, Politico published a letter signed by Denmark, Estonia, Finland, Latvia, Lithuania and Sweden, calling on the commission and EU’s General Affairs Council to fast-track Ukraine’s accession process to increase EU stability and minimise the chance of hostile actors—namely Hungary—further undermining the process.

Some EU member state publics, including Bulgaria and the Czech Republic, remain unconvinced about Ukraine’s membership potential. They are worried about the impact its accession might have on the EU economy and the rule of law, and how long it will take for Ukraine to prepare to become a fully-fledged member state. Ukrainians, on the other hand, remain positive about their relationship with the EU and European allies. In a survey conducted by ECFR, two-thirds of Ukrainians regard EU membership as just as important as NATO membership. The country’s citizens seek an anchoring not only in the transatlantic security alliance, but also in the European political bloc.

But even if the EU fast-tracks its accession, Ukraine will be unable to welcome the return of almost eight million Ukrainian refugees or benefit from Europe investing heavily in its economy and infrastructure without the EU first providing security guarantees. Joining the EU might stabilise the Ukraine politically; but it cannot be successful without being given assurances that a new war is unlikely, and that the EU will secure the resources needed for Ukraine to protect its country and its citizens.

EU enlargement therefore needs to favour the accession candidate countries in precarious geographical locations, such as Ukraine and Moldova, as well as their integration into joint defence initiatives. This will contribute to their internal security and stability, and benefit the EU by incorporating countries, like Ukraine, which have a heavily Western-trained army poised to add to the bloc’s external defence.

Convincing the European public

Crucially, for future EU enlargement to be successful, political will must align positively with public sentiment. It is vital that pro-accession European leaders effectively communicate the benefits of enlargement (including enhanced security, future geopolitical stability, and preventing the development of power vacuums which could heighten the influence of aggressive rival powers (such as Russia) to domestic audiences.

Countries such as Moldova, Ukraine, and states in the Western Balkans countries undergoing the accession process will also allow Europe to cement its influence in its wider neighbourhood. However, without targeted messaging and successful cut-through in the increasingly pervasive anti-EU narrative, anti-enlargement populism is likely to gain even more traction and further complicate decision-making. Even the most well-meaning politicians will struggle to advance the EU’s enlargement agenda amid diverse national priorities: now their challenge is balancing the urgency of security-driven enlargement, the EU’s institutional readiness, and ensuring accession is met with a positive public opinions.

Yet, to the pro-European public the benefits of an expanded and unified Europe are undeniable. Policymakers need to convince the deniers that EU enlargement will strengthen the bloc’s role on the global stage, foster regional stability—and ultimately reinforce the EU’s commitment to peace and democracy.