In August, at the request of Finland, the Swedish government sent fighter jets and a warship to help patrol the eastern airspace of Finland and the Gulf of Finland to counter Russian airspace incursions and drones deviating from their course during Ukrainian operations. Of particular importance is that the Swedish military forces and assets were placed under Finnish command and operated in accordance with Finnish rules of engagement. This is the latest example of the qualitative leap that Finland and Sweden — the two newest NATO members — have achieved in coordinating their defense activities. This is what Matti Pessu writes for Foreign Affairs.
"Over the past four years, the Nordic countries have significantly expanded their regional cooperation. Denmark, Finland, Iceland, Norway, and Sweden now have a new long-term defense strategy, a cross-border corridor for the movement of military forces, regular joint exercises, and an unprecedented degree of integration of command structures. In effect, these governments are building their own regional deterrence cluster: a group of like-minded countries that are deepening their military cooperation to strengthen deterrence and, if necessary, ensure NATO’s broader collective defense.
The Nordic model offers a glimpse of adaptive solutions that could help NATO remain resilient in uncertain times. Moscow’s appetite for risk-taking is growing; its military rearmament and escalating attacks on European infrastructure show that Russia poses a long-term threat to the Alliance. At the same time, the Trump administration is insisting that European allies take primary responsibility for the continent’s defense. Europeans must therefore deter an increasingly dangerous Russia with less American support.
To strengthen their deterrence and defense capabilities, member states on NATO’s expanded eastern flank — and in particular in the Baltic and Black Sea regions — need to build their own regional clusters and develop a dense network of bilateral and “minilateral” partnerships with their neighbors. Regionalization remains a taboo subject for most Alliance political leaders. After all, NATO is a collective defense alliance based on the principle of the indivisibility of security. Regional initiatives at the military level, however, would both enhance NATO’s effectiveness and contribute to the realization of the American vision of an alliance in which Europe plays a greater role.
Therefore, Scandinavian-style deterrence clusters are a win-win solution. At the same time, with its inconsistent and sometimes aggressive approach to Greenland and the North Atlantic, Washington risks undermining the positions of the very allies that are doing what it expects of them. The United States should use the recently signed Greenland agreement as an opportunity for a new beginning — to support Nordic defence initiatives and create incentives for other allies to follow suit.
A marriage of convenience
Defence cooperation between the Nordic countries took its current institutional form in 2009, when budget constraints in the context of recession prompted the five countries in the region to rethink their defence commitments. Finland and Sweden joined NATO members Denmark, Iceland and Norway in establishing the Nordic Defence Cooperation Organisation (NORDEFCO), with the main aim of reducing the cost of military procurement and arms acquisition. NORDEFCO achieved some early successes, including joint air force training flights over the relatively light airspace of northern Finland, Norway and Sweden. However, as the organization brought together NATO and non-NATO member states, bureaucratic obstacles and a relatively favorable security environment quickly weakened the momentum of joint arms acquisition initiatives.
It was only after the Russian invasion of Ukraine in 2014 that some of the Scandinavian countries began to see cooperation as a security imperative, rather than simply a way to save money. Finland and Sweden have established an unrestricted military partnership, which includes joint war planning. Norway, while continuing to put NATO first in its defense policy, has gradually embraced operational cooperation with its two non-Alliance neighbors in crisis situations. By 2020, when the three countries signed a trilateral declaration of intent, they were already conducting intensive joint exercises, exchanging intelligence on common threats, and discussing their national defense plans with a view to coordinated crisis response.
Any remaining restrictions on military cooperation between the Nordic countries were lifted when Finland and Sweden joined NATO in the wake of Russia’s full-scale invasion of Ukraine in 2022. The five countries in the region agreed that Moscow posed an imminent threat to their own security and that of Europe as a whole. Even Denmark, which had previously expressed reservations about regional cooperation, began to support collective defense initiatives. In 2023, it joined Finland, Norway and Sweden in developing the Nordic Airpower Concept, which will allow them to fight as a unified force using a total of 250 modern fighter jets.
Denmark also committed to providing personnel for the Swedish-led Forward Air Force Finland—a NATO battle group that rotates across northern Finland and Sweden. In 2024, when Denmark held the NORDEFCO presidency, the five governments also signed the "NORDEFCO Vision 2030" document, outlining their ambition to conduct joint operations that align with both their national defense interests and those of NATO. To provide the necessary logistical basis for cooperation between land forces, the initiative has created a seamless cross-border corridor for the movement of military forces in the Nordic region.
A clear division of responsibilities is also taking shape: Finland commands regional land operations, Norway hosts the regional headquarters for air operations, and Sweden becomes the logistics hub and transit zone for joint military operations in Northern Europe. Denmark, in turn, hosts the regional headquarters for special operations.
The Nordic Deterrence Cluster also functions seamlessly within the framework of NATO's collective defense system. The larger Allies in the Alliance - including France, Germany, the United Kingdom, and the United States - regularly conduct operations and exercises in the Nordic region together with their local partners, compensating for the lack of capabilities in areas such as intelligence, surveillance, and reconnaissance. The result is an increase in defense capabilities in NATO's Northwest Joint Operations Area, which covers the North Atlantic and includes key sea lanes, critical underwater infrastructure, as well as the Arctic and Scandinavian regions bordering key Russian strategic sites.
Imitation game
Deterrence clusters could become the future model for the defense organization on NATO's eastern flank.
In addition to NATO's Northwest Joint Operations Area, the Alliance has two other regional plans - Central, covering the Baltic states and Central Europe, and Southeastern, covering Turkey and the Balkans. Each of them has its own area of operations and a network of command centers. Governments in these two regions should follow the Scandinavian example and take the initiative to strengthen their own minilateral ties within NATO.
An obvious starting point is the southeastern Baltic Sea, which lies at the heart of NATO’s Central Area of Joint Operations. While the Baltic states share a common vulnerability to Russian penetration and aggression, their defense cooperation has remained limited since joining NATO. Estonia, Latvia, and Lithuania prefer to rely on partners outside the region, such as the United States. However, recent developments show that regional cooperation is gaining momentum: Estonia and Latvia have jointly acquired the IRIS-T air defense system, and all three countries are coordinating their HIMARS missile systems and building the Baltic Defense Line —a fortification project designed to direct, delay, and block a potential Russian ground invasion.
However, cooperation between the Baltic states would benefit from the creation of a more comprehensive minilateral mechanism, similar to NORDEFCO. In practice, this could mean coordinating national defense plans, conducting joint exercises, and sharing missile stocks for air defense systems. It could also include pooling HIMARS launchers to provide joint fire capabilities, better integrating national contributions to the Baltic defense line, and sharing unmanned vessels for surveillance of the maritime environment and underwater infrastructure. The aim would be for the three armies to be able to operate together as seamlessly as possible, creating a combined military power greater than the sum of their individual capabilities.
If implemented, such a format would also include Poland—one of Europe’s emerging military powers, which currently plays a limited role in the defense of the Baltic region. While Warsaw maintains a relatively stable defense partnership with Lithuania, including joint exercises and working groups, the two neighbors have so far failed to establish a common military exercise area in the Suwalki Corridor — a key strategic passage and vulnerable supply line connecting the Baltic states to continental Europe. A stronger minilateral framework would create a permanent mechanism for joint planning and consultation that could overcome local objections and differences in strategic priorities that have hampered negotiations on the corridor so far.
In extreme circumstances, subregional clusters could provide an additional security guarantee.
Within such a structure, Warsaw could strengthen regional defense by linking its "Eastern Shield" initiative — a national Polish program to build fortifications, fences, and surveillance systems along the borders with Russia and Belarus — to the Baltic Defense Line. In addition, Poland could provide ground-based air defense systems to support NATO's Baltic Air Patrol mission. The main goal should be to strengthen Poland's role as the leading guarantor of security in the Baltic region, alongside Germany, which has a permanent brigade in Lithuania.
The other NATO frontline area that would benefit most from the creation of a deterrence cluster is the Black Sea region, which falls within the Alliance's Southeastern Joint Operations Area. Bulgaria, Romania, and Turkey have difficulty cooperating due to their differing assessments of the threat posed by Russia. Building such a minilateral network here is undoubtedly more difficult than in the Scandinavian or Baltic regions. But in a NATO with a more European-led role, the other Allies will expect the Black Sea region to contribute more to collective defense, and the conditions for this are gradually improving.
The most promising area for expanding minilateral cooperation is maritime security. In July 2024, Bulgaria, Romania, and Turkey launched a joint mine clearance operation that led to the creation of a joint mission to protect energy infrastructure, telecommunications networks, and undersea pipelines owned and operated by the three Allies. This initial phase of a joint naval force could be further developed to cover more ambitious scenarios in the Black Sea — from maritime surveillance to territorial integrity protection, similar to the joint Finnish-Swedish naval group that performs such tasks in the Baltic Sea.
Air forces are another potentially promising area for cooperation along the Scandinavian model, especially in view of the growing capabilities of regional armies. Bulgaria is awaiting its F-16 fighters, Romania is about to acquire F-35s, and Turkey, which already has significant air power, is seeking to be re-integrated into the F-35 program. At the end of the first decade of the 21st century, the Scandinavian air forces began conducting weekly cross-border training flights, which paved the way for their current cooperation. More frequent exercises between the allies in the Black Sea region would be a logical first step towards improving interoperability.
It took the Nordic countries more than 15 years to reach their current level of cooperation. The rest of NATO’s eastern flank, however, cannot afford to wait that long. Russia could emerge from the war in Ukraine with greater military capabilities and less risk-averseness. Closer subregional cooperation would not only strengthen the security of vulnerable allies on the front line by improving their ability to respond together. It would also make NATO’s eastern flank more effective in deterring a Russian advance deeper into Europe — a goal that allies further from the front line should also share. Moreover, by strengthening the minilateral network, countries close to Russia would increase their ability to act together even before NATO takes collective action. In extreme circumstances, if the Alliance were paralyzed and unable to make a decision, subregional clusters would provide an additional security guarantee, allowing frontline Allies to respond together.
Directly interested party
The United States also has a direct interest in the development of deterrence clusters along NATO's eastern border regions. American officials have already outlined their vision for "NATO 3.0" - a restructured alliance in which European countries take the lead in their conventional defense, with the United States in a supporting role, providing an extended nuclear deterrent and some other capabilities. If the Europeans are to take primary responsibility for their conventional defense, subregional cooperative arrangements will be crucial. They should ensure a high degree of interoperability, joint arms procurement, planning and command capabilities, cross-border mobility, and even a certain division of military tasks between individual countries.
Scandinavian defense cooperation is the most developed model of such efforts, and the Scandinavian countries have already demonstrated their willingness to work with the United States on security issues related to Russia. For example, Finland and Norway are directing their intelligence capabilities to monitor what is happening on the Russian side of their borders. Finland also allows US electronic reconnaissance aircraft to use its airspace to monitor the Kola Peninsula, where the bulk of Russia’s nuclear retaliatory strike potential is concentrated. By preventing Russian dominance in the wider North Atlantic region, Scandinavian cooperation also contributes to the goal set out in the US National Security Strategy 2025 — maintaining a favorable balance of power in key regions of the world in cooperation with allies and partners.
Washington has every reason to view the Nordic countries as exemplary allies and to support their progress in regional cooperation. Yet the Trump administration’s approach to the region can be described as inconsistent at best. On the one hand, US officials welcome the Nordic countries’ efforts to increase defense spending — Denmark, Finland, Norway and Sweden already allocate or are on track to allocate 3% of GDP to defense by 2029, having committed to reaching the 5% of GDP target agreed in The Hague by 2035. On the other hand, US President Donald Trump has repeatedly expressed intentions to take control of Greenland — a nightmare scenario for the Nordic countries, which would put their common solidarity in conflict with each of their relations with the United States.
The Greenland agreement, signed by Washington, Copenhagen and Nuuk in September, should encourage the Trump administration to take a more active and constructive role in the security of the Arctic region. Until now, Washington has seen increased defense spending as a key factor in realizing the concept of "NATO 3.0". But an alliance led to a greater extent by Europe also needs allies who can use its growing capabilities as effectively and unhindered as possible. If the United States encourages and supports the development of Nordic-style minilateral networks in other key subregions, it will contribute to the creation of a more competent, capable, and stronger NATO 3.0".
* The original title of the article is "Can the Nordic Model Save NATO?"
Source: news.bg