A New Iron Curtain to Protect Europe from an Expansionist Russia

LOHOON: By any historical measure, the phrase "iron curtain" sends a shiver down the spine. When Winston Churchill used it in 1946, he was describing a continent divided by ideology, military power and fear, stretching "from Stettin in the Baltic to Trieste in the Adriatic". 

Nearly eight decades later, the metaphor has returned to European political language, but today the curtain is being raised not by Moscow but by Europe itself, this time to keep Russia out. Across the continent's eastern edge countries bordering Russia and its puppet ally Belarus are racing to fortify their frontiers. Fences, walls, bunkers, ditches, minefields and drones are appearing along hundreds of miles of borderland. From the Arctic north to the plains of Poland, a physical barrier is emerging, driven by a profound shift in Europe's sense of security. 

The post-cold war order, which relied on economic interdependence, international institutions, NATO and US security guarantees, is fraying. Russia's illegal full-scale invasion of Ukraine in 2022 shattered assumptions that large-scale war in Europe belonged to the past. Since then, neighbouring states have begun preparing for the possibility that Putin's ambitions may not stop at Kyiv. On Thursday, the Russian leader denied that he had any intention of attacking Europe, but then everyone remembers the same words four years ago when Russian troops were massing on Ukrainian borders. 

Nowhere is the sense of vulnerability clearer than in Finland, which shares an 832 mile border with Russia. For decades, this frontier was relatively quiet, even mundane. In remote north-eastern regions, Finns and Russians once crossed back and forth to buy groceries or visit friends. That era is ending. In 2023, Finland proposed building a fortified wall along roughly 18% of its border, at a cost exceeding $400 million. The project is expected to be completed next year. 

While Russia's invasion of Ukraine was the decisive catalyst, resulting in Finland joining NATO on 4 April 2023 marking a historic shift from its long-standing military non-alignment, Finnish officials also point to a surge in Russians fleeing conscription, which exposed how ill-prepared the border infrastructure was for sudden pressure. Two years ago, Finland passed legislation allowing the construction of stronger and taller barriers. Previous fences, often wooden, had been designed merely to keep livestock from wandering across the border. 

Now, eight fortified border posts have been erected, including north of the Arctic Circle, with additional obstacles concentrated in the country's southern regions. Even sparsely populated areas are being reinforced, signalling how thoroughly Helsinki's strategic outlook has changed. The border is no longer treated as a peripheral concern, but as a frontline. 

Finland's move is part of a wider regional trend. Estonia was among the first to act, announcing plans in August 2015 to build a fence along its eastern border with Russia, following Moscow's illegal annexation of Crimea the year before. What began as a limited security measure has since evolved into a much broader project. Last year, Estonia, Latvia, Lithuania and Poland proposed a vast new defensive wall stretching some 434 miles, at a cost of almost $3 billion. Construction and planning have accelerated amid fears that a ceasefire in Ukraine could free up Russian forces for redeployment elsewhere, including towards NATO's eastern flank. 

Latvia plans to invest around $350 million over the coming years to reinforce its 240-mile border with Russia. Lithuania is preparing a 30-mile defensive line, while Poland has begun building a permanent fence along its border with Belarus, which it views as a potential staging ground for Russian pressure or proxy action. 

These barriers are not limited to fences. They form part of a layered defence strategy that includes anti-tank ditches, massive concrete blocks, roadblocks and heavy metal gates. Some of the most striking features are 15-tonne concrete "dragon's teeth", designed to halt or slow armoured vehicles. In certain areas, minefields and blocked bridgeheads are planned to further restrict movement. Lithuania is preparing up to 30 miles of reclamation ditches, bridges pre-wired for demolition, and even trees designated to be felled across roads in an emergency. 

The aim is to slow an advancing force, buying time for defenders and allies to respond. Beyond surface obstacles, the Baltic states are investing heavily in underground protection. More than 1,000 bunkers, ammunition depots and supply shelters are planned along roughly 600 miles of border territory. These bunkers, typically around 377 square feet in size, are designed to house up to ten soldiers and withstand artillery strikes. 

In a further sign of how dramatically security thinking has shifted, several countries have moved away from long-standing arms control commitments. This year, the Baltic states, Finland and Poland announced their intention to withdraw from the 1997 treaty banning antipersonnel land mines. Lithuania has also revoked its pledge under a cluster munitions treaty, while Poland confirmed in June that minefields would form part of its "East Shield" border defence plan. These decisions have drawn criticism from humanitarian groups, but governments argue they reflect the realities of deterrence against a heavily armed and aggressive neighbour. 

Physical barriers are only one part of the new iron curtain. The borders will also be guarded by advanced technology, early warning systems and rapid-response units. Last year Lithuania, Latvia, Estonia, Poland, Finland and Norway met in Riga to begin planning an ambitious 1,850-mile "drone wall". This system would combine radar, sensors and electronic warfare tools to detect and neutralise hostile drones. Once an object crosses the border, it could be identified and tracked within seconds by reconnaissance drones, creating a dense surveillance network along Europe's eastern edge. 

The project depends on close cooperation among participating states. Estonian firms are already designing drones capable of operating in the complex terrain that characterises the region, from forests and swamps to lakes and wetlands. This landscape has historically complicated military planning, but new technology promises to turn geography into an advantage. 

European leaders are acutely aware of the dangers of overconfidence in static defences. The Maginot Line, the vast system of fortifications France built in the 1930s, looms large as a cautionary tale. While formidable on paper, it failed to prevent German forces from bypassing it through Belgium and the Ardennes Forest during the second world war. Today's planners stress that the new barriers are not intended to make borders impenetrable; rather, they are meant to deter aggression and shape the nature of any potential invasion. By channelling movement into predictable routes, defences can slow an attacker and reduce strategic surprise. 

Unlike the Maginot Line, these projects emphasise regional coordination. In the 1930s, the failure to fully integrate Belgium into French defensive planning left a fatal gap. In contrast, today's eastern European states are seeking collective solutions, sharing intelligence, technology and infrastructure. 

Underlying all these efforts is a shared anxiety about what comes next. If fighting in Ukraine were to pause or end, Baltic leaders fear that the Kremlin could turn its attention elsewhere. Even without open conflict, hybrid tactics such as cyberattacks, border provocations or the manipulation of migration flows remain a concern. For countries that regained independence only a generation ago, memories of domination by Moscow are not abstract history. 

The new walls, fences and drone networks are as much psychological as physical, signalling resolve to both domestic audiences and potential adversaries. This new iron curtain is not a symbol of ideological division in the way Churchill described in 1946; it is a manifestation of fear, caution and preparedness in an era when Europe's security assumptions have been upended. Whether these fortifications will ever be tested remains unknown. But for now, the message from Europe's eastern borderlands is clear. After Putin's savagery in Ukraine, having emphatically denied that Russia would invade the country, complacency is no longer option. 

John Dobson is a former British diplomat, who also worked in UK Prime Minister John Major's office between 1995 and 1998. He is currently a visiting fellow at the University of Plymouth.