Robert C. Castel: The Risks of Ukraine's EU Membership

Geopolitical virtue-signaling can easily turn into a security crisis.

Ukrainian President Volodymyr Zelensky (Photo: AFP)

No change — no matter how desirable — ever arrives alone: it brings with itself benefits, costs, and damages. The ratio of these three factors can dramatically shift over time. What shines as an advantage today may become a heavy burden tomorrow. Whether a change proves beneficial in the end depends significantly on the vantage point from which one views the world map. Therefore, anyone who is only willing to discuss a given change from a single perspective, at a single moment in time, and from a single viewpoint, is not offering analysis but engaging in propaganda.

And Ukraine’s accession to the European Union is no exception.

I accept that, from the western edge of the continent, in the first half of 2025, Ukraine’s EU membership may seem like a dairy product made entirely of cheese and no holes. However, when considered from elsewhere and with a broader time horizon, the same decision appears in an entirely different light. As is my habit, I will once again play the devil’s advocate and introduce a few perspectives into the discourse that those celebrating the accession so elegantly ignore. This article offers a rapid assessment of the national security aspects of Ukraine’s EU membership — more precisely, the repercussions that are relevant to internal security.

Let's begin with one of the most fundamental, yet often overlooked factors: the length of borders. With Ukraine’s accession, the European Union’s shared border with Russia and Belarus will practically double. This fact alone represents a clear security threat, as doubling border protection capacity — whether in manpower or technology — will impose a heavy financial burden on Europe.

To grasp the scale and magnitude of these costs, consider the evolution of Frontex’s budget from 2014 to the present day. The level of border security deemed acceptable by the EU in 2014 cost the EU’s citizens €100 million annually. Ten years later, that amount has increased ninefold, reaching €900 million, with the 2027 budget projected at €1.27 billion. Meanwhile, the length of borders to be monitored has not increased even marginally. With the expected doubling of EU borders, we are likely to find ourselves in the €2.5–3 billion range.

No less disconcerting is the question of the 10–12 million Russian-speaking minority living in Ukraine. At first glance, this may seem like an issue exclusive to the Baltics. In reality, the EU's largest Russian ethnic, or Russian-speaking minority populations reside much farther west, in Germany (nearly a quarter million) and Spain (almost one hundred thousand). With Ukraine’s accession, this ethnic group would become the EU’s most populous minority. This “virtual Novorossiya” would outnumber the populations of two-thirds of EU member states. History has repeatedly shown that the presence of large, concentrated ethnic minorities poses serious geopolitical and national security risks. Is Europe truly prepared for this new and sensitive internal reality?

Migration challenges will also emerge. While the number of maritime migration routes in the Black Sea region is currently limited, Ukraine’s EU membership could open yet another gateway into the continent. The extended land and sea borders will place further significant demands on a Europe already under severe migratory pressure. According to last year’s data registered by Frontex, migration routes are gradually shifting toward the continent’s western and eastern edges. Comparing this trend with the doubling of illegal border crossings along the EU’s eastern land border, it becomes clear that Ukraine’s EU accession may create a bridge between the two already existing routes.

Ukraine’s vulnerability to cyber threats adds yet another layer of problems to consider. Even before 2022, the Russia–Ukraine war was an intense battlefield of cyberwarfare, and it will likely remain so. As the concept of cyber vulnerability is fairly abstract, it’s worth illustrating the scale of such attacks through a few examples. In December 2015, a cyberattack using the BlackEnergy malware struck Ukraine’s energy infrastructure, leaving a quarter of a million people without electricity.

A year later, a similar attack near Kyiv caused widespread energy disruptions. In June 2017, the infamous NotPetya malware attack became one of the most devastating cyber strikes in history. Europe, for now, remains an outside observer in this conflict. But with Ukraine’s accession, its cyber war instantly becomes Europe’s cyber war. The situation is further complicated by the fact that Ukraine brings with it a vast telecommunications infrastructure, some parts of which are highly outdated. This creates a substantial attack surface for adversaries.

The issue of intelligence and counter-intelligence is equally serious. Alongside cyberwarfare, the intelligence war underway in Ukraine would become an internal matter for Europe. What previously deflected off the EU’s external borders will now ricochet inside them. This fundamentally alters the continent’s intelligence strategy, consumes resources, and could generate new internal tensions. Political divisions within the EU regarding Ukraine already significantly undermine cohesion in this area.

Until Ukraine normalizes its political relations with its immediate neighbors, we cannot expect any substantial improvement in inter-agency intelligence cooperation. It would be a mistake to think tensions will disappear just because we wrap them in shiny blue foil and decorate them with yellow stars. The tensions will persist—and haunt us for decades to come.

And to cap it all, we also have Russian information operations. Until now, these have primarily targeted Ukraine, but with the country's accession, they will focus on the entire EU. Three major information campaigns against Ukraine stand out. The first was part of the hybrid campaign surrounding the annexation of Crimea. The second accompanied the protracted Donbas campaign. And third—perhaps most consequential—Russian information warfare played a critical role in preparing and supporting the current war. These information operations will not occur in a vacuum. The Russian minority in Ukraine and the broader Russian diaspora across Europe can act as amplifiers of Russian propaganda, destabilizing European societies.

Organized crime may also enter a new dimension. The post-Soviet criminal underworld that emerged after the collapse of the Soviet Union will, with Ukraine’s accession, become a European problem. Due to the Biden administration’s weak border policies, the United States has already experienced the consequences of external criminal networks infiltrating the country.

Europe could face a similar fate — compounded by the fact that the war has led to the accumulation of massive stockpiles of weapons and explosives in Ukraine. These could easily seep back into the EU, further destabilizing an already tense Europe. It is a tragic irony that the continent so determined to disarm its own citizens may soon find itself surfing a tsunami of illegal weapons.

So the challenges facing the European Union are far more severe than what official propaganda suggests. We are witnessing an accelerating role reversal between Europe and the United States: while America grows increasingly cautious about engaging in foreign conflicts, Europe is diving headfirst—blindly and zealously—into crises it neither understands nor can manage. As Americans fortify their own borders with growing determination, Europe appears intent on importing its problems.

Today, Europe stands at a crossroads: ignoring geopolitical realities could carry grave consequences.

Ukraine’s EU membership is not merely a gesture of solidarity. It is a strategic decision carrying long-term national security risks. It is high time to weigh the consequences with clear-headed pragmatism, before geopolitical virtue-signaling turns into a full-blown security crisis.

The author is a security policy expert at the Center for Fundamental Rights and a senior fellow at our newspaper.

Cover photo: Ukrainian President Volodymyr Zelensky (Photo: AFP)