Since Russia’s full-scale invasion of Ukraine in February 2022, analysts have frequently argued that the geopolitical centre of gravity of Europe has moved eastward[1]. Countries on NATO’s eastern flank—particularly Poland and the Baltic states—gained influence as their long-standing warnings about Russian revisionism were vindicated. Security debates increasingly reflected the priorities of states closest to the conflict.
Three years later, however, a second shift appears to be underway. While the eastward movement remains relevant, Europe’s strategic dynamism is increasingly concentrated along a Northern Arc stretching from the United Kingdom through the Nordic and Baltic countries to Poland. NATO enlargement to Finland and Sweden, growing defence cooperation among Northern European states, and the emergence of the Baltic Sea as a strategically integrated space have reinforced this trend.
Yet the most important question may not be whether Europe is moving north. Rather, it is what this shift means for Central Europe. The emergence of a Northern Arc risks weakening traditional Central European formats while simultaneously creating a strategic imperative to develop new frameworks connecting the Baltic and Black Sea regions. This challenge creates opportunities for both regional actors and external partners, particularly the United Kingdom, to help shape a more coherent security architecture for Europe’s eastern flank.
The Emergence of the Northern Arc
The geopolitical significance of Northern Europe has increased dramatically since 2022.
The accession of Finland and Sweden to NATO transformed the strategic environment of the Baltic Sea. Combined with the growing military capabilities of Poland, the technological and industrial strengths of the Nordic countries, and Britain’s continued engagement in European security, a new geopolitical space has begun to emerge.
Several factors underpin this development. First, Northern European countries share remarkably similar threat perceptions. They have generally adopted robust positions towards Russia, demonstrated strong support for Ukraine and invested heavily in defence capabilities.
Second, many of these countries have become leaders in military modernization. Poland is building one of Europe’s strongest conventional armed forces. Finland and Sweden bring significant defence capabilities and advanced defence industries. The Baltic states have become pioneers in resilience, cyber security and societal preparedness.
Third, the region combines security credibility with economic dynamism. Poland is among Europe’s fastest-growing economies, while the Nordic countries remain global leaders in innovation, technology and competitiveness.
Finally, a growing web of institutional arrangements reinforces these trends. The Joint Expeditionary Force, Nordic Defence Cooperation, Nordic-Baltic cooperation formats and various bilateral partnerships have all contributed to deeper strategic coordination across Northern Europe.
Taken together, these developments suggest that the continent’s geopolitical centre of gravity is no longer located exclusively within the traditional Franco-German core. Instead, a new northern strategic space is emerging as one of Europe’s most important geopolitical regions.
The Central European Challenge
While the rise of the Northern Arc presents an opportunity for enhanced security cooperation with like-minded countries and closer strategic alignment in this vector, it creates a complex strategic dilemma for Central European countries.
For much of the post-Cold War period, regional cooperation was organised around a set of overlapping frameworks involving smaller or larger groupings of countries. The Visegrád Group (V4), the Three Seas Initiative or the Bucharest Nine, while topically and politically very different, had one thing in common – all sought to strengthen cooperation among countries situated between Germany and Russia.
Today, many of these frameworks face significant challenges. The Visegrád Group has been weakened by divergent approaches especially to Russia and war in Ukraine. Poland and Hungary, once important actors behind many of these regional cooperation frameworks, in particularly V4, increasingly found themselves pursuing different strategic agendas. Political volatility in parts of Central Europe further complicates efforts to develop coherent regional positions on security and defence.
At the same time, Poland—the region’s largest military and economic power—is increasingly investing diplomatic and strategic capital in relationships with Nordic and Baltic partners. This development is understandable. Northern European cooperation often involves countries with strong security cultures, substantial defence investments and broadly aligned strategic outlooks.
Yet Poland’s northern orientation and increasing strategic confidence also creates a risk. If the region’s principal strategic actor increasingly looks northward (or outwards), it can weaken its links with other countries in broader Central European region?
The challenge is particularly evident when viewed from a wider geographic perspective. Europe’s eastern flank stretches from the Arctic and Baltic regions to the Black Sea. While the northern part of this space is becoming increasingly integrated, the central and southern segments remain fragmented.
The result is a flank that is coherent in the north and fragmented in the south. Poland has chosen to look north. That choice is rational, but it risks leaving five exposed frontline states strategically orphaned: reliably Atlanticist Romania and Bulgaria on the Black Sea, and a recalibrating Czechia, Slovakia and Hungary in the centre. Poland and Britain as two of NATO’s most capable members can be the bridge towards a new security architecture which includes Central Europe rather than leaving a capability and interoperability gap on NATO’s eastern flank.
Towards a Baltic–Black Sea Security Architecture
Bridging the gap requires moving beyond traditional concepts of regional cooperation. The key strategic objective should be the development of a Baltic–Black Sea security architecture capable of integrating defence planning, military mobility, resilience and economic security across Europe’s eastern flank.
Such an architecture would not replace NATO. Nor would it seek to duplicate European Union structures. Instead, it would provide an additional layer of regional coordination among states facing common security challenges. And it would allow to include Ukraine as an indispensable actor in this strategic area.
Several existing frameworks could provide foundations for this effort. The first is the Bucharest Nine. Established in 2015, the B9 has played an important role in coordinating positions among NATO’s eastern members. However, it remains primarily a consultative forum. The next stage of its development could involve a stronger operational dimension, including cooperation on defence-industrial production, military mobility, air and missile defence, critical infrastructure protection and cooperation on developing stronger whole-of-society resilience.
The second is the Three Seas Initiative. Originally conceived as an infrastructure and connectivity project, the initiative increasingly intersects with security concerns. Energy corridors, digital networks, transport infrastructure and ports have become critical components of national security. A stronger security dimension within the Three Seas Initiative could help connect geoeconomic and defence priorities across the region. At the end, development of infrastructure needs to go hand in hand with building collective economic security, cooperation to protect vital infrastructure, and again make societies more resilient.
Rather than creating entirely new institutions, policymakers should focus on strengthening these existing frameworks and adapting them to the realities of long-term strategic competition.
Britain´s Role in a New Regional Security Order
The United Kingdom is uniquely positioned to contribute to this process.
Since Brexit, London has sought new mechanisms for influencing European security. The British approach has increasingly relied on flexible coalitions and practical cooperation rather than formal institutional integration.
The success of the Joint Expeditionary Force demonstrates the effectiveness of this model. However, the lesson is not necessarily that JEF should expand geographically. From a British perspective, expansion risks diluting the cohesion and effectiveness that make the framework successful.
Instead, Britain could help facilitate a complementary security architecture in Central Europe and along the Baltic-Black Sea axis.
This could involve deeper engagement with the Bucharest Nine minus the Baltic States who already participate in JEF– for example B9+ format –, stronger participation in Three Seas projects, expanded defence-industrial cooperation and greater support for military mobility initiatives linking Northern Europe to the Black Sea region. A new rapid response and training capability formed of the Bucharest 6 could be a vital bridge within NATO’s “Framework Nations Concept” rubric.
Britain’s comparative advantages are particularly relevant in areas such as intelligence cooperation, defence innovation, maritime security, cyber resilience and expeditionary capabilities. Combined with Poland’s growing military power and Romania’s strategic position in the Black Sea region, British engagement could help strengthen the coherence of Europe’s eastern flank. Defence technological cooperation between UK and regional actors, such as Poland or Czechia that already have well-developed and versatile defence industry, could also create new security dynamics. Importantly, such cooperation would also reinforce NATO’s broader deterrence posture without requiring major institutional innovation.
Conclusion
The geopolitical consequences of Russia’s invasion of Ukraine continue to reshape Europe in profound ways. While the immediate effect of the war was an eastward shift in Europe’s strategic centre of gravity, recent developments suggest that a Northern Arc stretching from the United Kingdom through the Nordic and Baltic countries to Poland is becoming one of the continent’s most important geopolitical spaces.
The significance of this transformation extends beyond Northern Europe itself. As strategic attention and political capital increasingly flow northward, traditional Central European frameworks risk losing relevance. This could create fragmentation across Europe’s eastern flank at precisely the moment when greater strategic coherence is required.
The challenge for policymakers is therefore not to choose between Northern Europe and Central Europe. It is to ensure that the emerging Northern Arc is connected to a broader Baltic–Black Sea security architecture capable of addressing the long-term challenges posed by Russian revisionism and geopolitical competition.
Existing initiatives such as the Bucharest Nine and the Three Seas Initiative provide promising foundations for this effort. External partners, particularly the United Kingdom, can play an important role in supporting their evolution.
The defining geopolitical question for the next decade may therefore be not whether Europe is moving north, but whether the continent can successfully connect its increasingly integrated northern security space with a coherent strategic framework stretching from the Baltic Sea to the Black Sea.
Policy proposals:
1. A new rapid response framework for Central Europe led by Poland and the UK to increase interoperability
2. Increased military cooperation and coordination between Central Europe and the UK
3. An increased focus on societal resilience taking examples from Nordic countries
4. Hardening of infrastructure and factories from potential Russian sabotage attacks