Regional Security Complexes – Europe 2024-2025

Regional Security Complexes – Europe 2024-2025

by Milan Hiber and Milan Ranković 

Introduction 

Europe represents a crucial security complex, whose internal and external security relations have a large impact on international relations and security. It is a region with many traditional amities and enmities and ever-changing security structures and dynamics, which influence relations to this day. It is in Europe that the Westphalian state, a foundational element of RSCT, was created, while also including the European Union as the first supranational organisation. This regional security complex is also host to one of the most significant ongoing conflicts in the world, the Russia-Ukraine war, a conflict that has greatly changed international security relations and altered the security landscape even of other RSCs. The Complex is also significant as it includes the European Union (EU), which could be considered one of the most complete security communities when viewed as a subcomplex, or even a sui generis actor in the complex.  

As Buzan and Waever note, the Roman Empire represented a unified European large-scale “security order” (Buzan and Waever 2003, 345). Europe has gone through many security formations since. Only in the twentieth century, it had gone through two World Wars, a Cold War, a moment of domination by U.S. unipolarity, and then a form of bipolarity again. The principal actor went from being Westphalian states focused on sovereignty, to colonial empires, to post-imperial states, to creating a sui generis supranational European Union. This historical legacy has significantly shaped security relations within the complex. While traditional enmities and amities often remained relevant, the main result of such a complex history, at least for most Western European states, was Europe’s other being Europe’s own past (Buzan and Waever 2003, 356).  

Regional Level 

The European Union is among the most significant actors within the European RSC. The EU, however, can also be analysed as a subcomplex (e.g. Buzan and Waever 2003, 27, 58). It includes many (27), but not all, European states, and is not the only significant power on the European continent. It acts independently towards great powers, as well as influencing regional and sub-regional balances of power. However, it can also be analysed as a subcomplex, as it is still a collection of states with significant sovereignty and autonomy, whose ideas and perceived security interests might not always align. As a subcomplex, it has its own main actors (e.g. Germany, France), security relations and dynamics. Recent trends (such as the Readiness 2030 plan), however, show that it is primarily heading in the direction of security integration, and can thus be primarily seen as its own actor in the wider RSC. 

There are other subcomplexes within the RSC, such as Western Balkans, whose dynamics can influence security, especially in South Eastern Europe. This influence, however, is limited by the lack of significant powers and the lack of security cooperation and integration in the subcomplex. It is primarily influenced by the EU, as all of the members of this subcomplex are officially attempting to join the EU, as well as other global powers, such as Russia, China and the U.S  

Another important actor within the European RSC is Russia, a “superpower on the decline”, becoming a great power (Ibid. 36). Even if it cannot claim the superpower status of the Soviet Union, today’s Russia is a significant global actor that shapes security regimes with Europe and the whole world. Russia’s invasion of Ukraine has been a major security event that has affected global security dynamics. While Buzan and Waever place it within the post-Soviet space, as its own RSC (Buzan and Waever 2003, 397-8), the context of the last two decades has significantly shifted. Russia’s most significant security relations are those with Ukraine (since the 2014 crisis and 2022 invasion), but its security interactions with the rest of Europe have been of major significance as well. The European Union has been a strong supporter of Ukraine (European Commission), supplying the country with ammunition, funds and other resources, while enacting sanctions and resolutions against Russia. The war has also shifted security relations in the rest of the continent by influencing certain traditionally neutral states to join NATO (Finland, Sweden), and has reignited the idea of rearming European militaries and developing their defence industry (e.g. the  Readiness 2030 plan). Because of all of this, the post-Soviet space could in fact be seen as a subcomplex within the European RSC.  

Similarly, the Western Balkans region, consisting of 6 entities on the Balkan peninsula that have yet to join the European Union (Albania, Bosnia and Herzegovina, Northern Macedonia, Montenegro, Serbia and Kosovo), can be analyzed as another subcomplex, significantly influenced by most of these countries histories of both life in a common state (Yugoslavia in its various forms), as well as war and dissolution of said state. While it is true that traditional enmities still plague the subcomplex, all of these countries today are officially attempting to join the EU, and three of them have joined NATO. These similar goals have led to certain levels of cooperation, including various regional initiatives, often facilitated by the EU (Berlin Process, Open Balkan, etc.). However, Russia’s influence on some of these states, primarily Serbia (as well as the Republic of Srpska in B&H) and the general slow advance of European integration, has limited the level of security integration in the region (e.g. Robert Lansing Institute 2025). 

Ukraine itself could be considered a regional power, significant primarily in the CIS subregion. Though not considered a regional power by Buzan and Waever (Buzan and Waever 2003, 55), Ukraine’s years-long defense against Russia’s aggression, with the support of major actors within the European RSC, have proven that Ukraine is a significant actor itself. 

Recent Regional Security Dynamics & Issues

The specifics of the RSC as it exists today have been influenced by the process of European integration. This process has transformed historical amities and enmities into a constructive power, creating a significant security complex, which in turn started a transformation into a security actor in its own right. The other main process has been Russia’s decline from superpower status and its attempts to hold onto the power and status associated with it. This has resulted in projecting its power in the (ex-)CIS region (Ukraine, Georgia, Moldova/Transnistria, Armenia), as well as other parts of Europe (e.g. Serbia). 

The War in Ukraine remains the primary issue shaping the security relations within the RSC. Most other issues stem from or are influenced by this war. Otherwise, there is also the issue of European (primarily EU) security dependence – the EU has been attempting to become an independent and more significant actor in international security, less dependent on the U.S. There is also energy dependence – a significant factor of security relations within this RSC has been the dependence of the EU on Russian gas. This dependence has been securitised following the war in Ukraine and further polarisation of the two major powers in the Complex. 

The August meeting of Vladimir Putin and Donald Trump in Alaska didn’t result in a solution for the war (Atlantic Council, 2025). It seems that those great powers don’t rely much on European capability to solve their internal crisis on their soil. Deepening of the conflict and loosening of the EU-NATO relationship a potential threat to EU security. An important question then arises. Is Europe ready to potentially defend itself without American help, as it has since the end of World War II? It is also important to follow the dynamics of the unfolding  Israel-Palestine conflict and examine its potential influence on European regional security dynamics. Especially because those regional security complexes are interdependent based on their geopolitical position, touching each other.   

 Regional Structure 

The European Regional security complex contains two major poles: the European Union and the Russian Federation. These are the two most significant actors in the region, and often have very opposed security interests. They also both tend to exert their influence over the smaller powers, such as the Western Balkan and post-Soviet subcomplexes.  

The EU is still not completely integrated, due to the lack of consensus among member states on security and defence matters, leading to the Union having centres of power even within itself. On economic basics, it “seems“ well integrated (Börzel, Risse, 2019), but there are problems in the functioning of the main EU governing bodies. Power is not equally distributed; some of the member states are significant powers in their own right and are thus able to significantly influence policy decision-making (European Union, 2025). This uneven balance of power can affect one of their priorities to “strengthen EU security and defence” (as stated in the Union’s Strategic Agenda for 2024-2029: European Union, 2025, as well as the Readiness 2030 plan), as certain governments remain against the idea of furthering political and security integration and developing a common European army. Some member states remain militarily neutral (e.g. Austria, though we have seen in the Swedish and Finnish cases that neutrality is not necessarily permanent), while others remain unsure of the EU’s stance towards Ukraine and Russia (e.g. Hungary, Slovakia). 

Further, there are conflicts between some EU countries that are making it harder for them to make a unique approach. Especially in the EU-Hungary relations, and having in mind the divide on security issues among principal actors (countries) within the EU. This amity and enmity divide is best seen in questions like the war in  Ukraine or recognising Palestine. The EU missed the opportunity to integrate other countries that are not yet members and aspire to join it. Whole Europe, under the auspices of the EU, could have given more reliable results in making better and even power distribution. Economic imbalance further leads to political and security challenges.  

When Donald Trump came into power as the U.S. president, the question of the EU’s strategic autonomy towards NATO arose. The majority of EU member states are part of this military alliance. Finland and Sweden recently joined as well, influencing the balance of power in EU-Russia-NATO relations. Two questions arose: Can the possibility of Ukraine joining NATO deter Russian intrusion further into Europe? Secondly, can the EU form a military and gain security independence from the U.S.? 

Securitizing moves

As Buzan and Waever noted, one of the most important parts of security discourse in Europe after the Cold War was the discourse on avoiding repeating Europe’s past of fragmentation, power balancing, and wars (Buzan and Waever 2003, 356). While this has been mostly achieved within the EU, there has been a striking return to these issues with the war in Ukraine. At the time, Europe’s other was presented as “Europe’s past”, not “Russia nor Islamic Fundamentalism” (ibid.). This has, arguably, changed, with the war in Ukraine.  

We have seen attempted securitising moves from both of the ‘poles’ in recent years. The Russian invasion of Ukraine, officially a “special military operation”, was justified through the securitisation of Ukraine’s alleged attempts to join NATO. An ex-Soviet country on Russia’s border joining the Alliance was presented as an existential threat towards Russia.  

The war in Ukraine was then securitised by the EU and European NATO members. The invasion was presented as a threat to European security. This was especially true for countries that bordered Russia or Ukraine, such as Finland (which abandoned traditional neutrality and joined NATO in 2023) and Poland.  

These securitising moves have reinforced the polarisation that has already existed, and which was exacerbated by the war in Ukraine. On the other hand, they have intensified the EU’s unity and actorship regarding international security. The EU exists as something between a global power and a subregional security complex in its own right, though it seems to be moving towards the former. This can be seen through examples such as the ReArm Europe/Readiness 2030 plan (European Parliament) and increased defence, as part of the wider attempts to lessen defence dependency on the U.S., and increase the EU’s security capabilities (see the Kiel Report on European rearmament, for example). 

There has been further securitisation of European integration itself. Though this was already noticed over 20 years ago (ibid. 356), it has intensified in recent years, with eurosceptic, often right-wing parties becoming significant political options in many EU members (e.g. France, Germany, Spain, Portugal – see ECFR, Politico).  

Interregional and global level 

Geographically speaking, Europe as RSC is overlapping with one of the main focal points in the world, the Middle East, especially regarding the EU stance on Israel and Palestinian question (Deutsche Welle, 2025). There, we can identify the Caucasus as one of the potential buffer (insulating) zones, looking at it as a „mini-complex” (Buzan, Waever, 2003, p.111). Also, this geopolitical part of the world is full of other conflicts that shape its regional dynamics. Especially on the interregional level when looking backwards (i.e Syrian migrant crisis) with Europe.  

The U.S. and China, as the two global superpowers, also exert their influence in the region. The U.S. has historically been significant as (Western) Europe’s protector (e.g. Pantheon Sorbonne, 2019), though this dynamic has changed recently. The EU, as a main pillar of the European continent, can act as an independent actor, but not in its full capacity, having in mind its military dependence on NATO (NATO, 2025). The Union is still attempting to find its place as an independent strategic actor in the current global order, but doing that requires further integration and perhaps even federalisation (Fägersten et al, 2025).  

 China’s influence has primarily been economic, with significant investments in certain European states (Atlantic Council, 2025). Relations with China are important for the EU, as they are one of its biggest trading partners (European Commission, accessed: 28.8.2025). Economic interdependence with other great powers, such as the US and China, significantly impacts the EU’s ability to act as a fully independent actor.  

Continuities, Changes, and Future Outlook   

The ongoing war in Ukraine represents the main security trend for the European Union. Even though Ukraine isn’t a member of the EU, it has been a candidate since 2022 (European Commission). Still, the war is an important geopolitical challenge for the EU to face, which is especially true when taking into account the discussion about the armament of Ukrainian forces. This could be a potential source of escalation within the EU countries, due to the disagreement from certain member states, such as Hungary and Slovakia, regarding the EU’s official foreign policy towards the war. Further, Poland was one of the main suppliers of Ukrainian troops at the beginning of the crisis and during the war (National Security Bureau, 2025), but lately stopped (Defencenews, 2024), over disagreements regarding the import of Ukrainian grain. The majority of the Union’s members, as well as EU officials, remain staunchly in support of Ukraine, however. For the EU, “the future of Ukraine is fundamental to the future of Europe as a whole“. (European Commission). So it will remain as one of the vital focal points for Europe in the remaining years.  

This is not the only challenge for European security, as there have also been disagreements regarding the recognition of  Palestine. This question is crucial, as the European and Asian regional security complexes tend to interact and even overlap at points. A potential spillover of the Israel-Palestine conflict could cause the emerging threat of a potential new migrant crisis, as well as weaken the unity of the EU subcomplex due to major disagreements over the conflict.  

Regarding future scenarios, it is very likely that the EU will gain security independence from NATO. This scenario could be desirable for the EU, and would be plausible if member states managed to overcome their internal disputes. Continuation without a solution for the Ukraine war will lead to more disintegration, opening frozen conflicts in the EU neighbourhood, such as in the Balkans, having in mind Kosovo-Serbia relations, or the Moldova question (Euronews, 2024). It is most likely that the EU will always have problems with its eastern neighbourhood, as seen in recent elections in Moldova (CNN 2025) and Georgia (Politico 2025), where Russian interference and European integration were among the most important topics, serving as a sort of proxy political battle between the two major poles of power within the European RSC. In Georgia, this led to the rise of euro-scepticism and right-wing populism, resulting in a political crisis, while Moldova witnessed the victory of pro-European parties and a continuation of its process of European integration. 

The Moldovan elections reaffirmed “enduring support for the European future” of that country (European Council, 2025). Along with the Ukraine war, the unravelling of events in Moldova can be perceived as an act of deterring Russian influence in the European continent (European Council, 2025). On the other hand, Georgia has problems with “democratic backsliding” through the need to reform the election framework in the 2024 elections (European Commission, 2025). Both Moldova and Georgia are buffer zones in the EU, and are affected by the relations between Russia and the Union.  

Further, continuing disagreements over key global issues could prevent further European integration. This, combined with the rise of Eurosceptic forces within the EU, could lead to a return to the primacy of the sovereign state. This is an especially significant issue, seeing as recent years have shown major cleavages within the EU regarding the conflicts in Ukraine and Palestine. Further, the interaction between the two major powers within the European RSC, the EU and Russia, has spilt over to other countries in the region, such as the Western Balkans subcomplex, as well as Moldova and Georgia.                

Conclusion 

Europe will stay entangled with the Ukraine conflict for the near future. The EU, as a primary actor within the European RSC, is still significantly influenced by the penetration of great powers. The amity–enmity axis will make further cleavages, especially having in mind the EU–Hungary relations. This is still one of the most important EU’s internal challenges, both for its energy security and unity of political leadership. Besides the war in Ukraine, a latent danger represents conflict in the Middle East and the EU’s stance on the Palestinian issue. The year 2026 will be key in determining the nature of Europe’s changing security relations with the U.S. Recent attempts by U.S. President Trump to conduct negotiations and reach an armistice between Russia and Ukraine, even though they have not been fruitful, have shown the interest of the world’s largest superpower to resolve this conflict (Politico 2025, CNN 2025). We can expect these attempts to continue and intensify next year, especially as 2026 will be a mid-term election year for the U.S. Congress, which could influence U.S. foreign policy. The coming years will be a very important test for the durability of a European political community project (European Council, 2025). Europe has always been a crossroad of great powers, so every event on its geopolitical landscape has always had broader implications for international security. 

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