Abstract
The EU is now faced with a highly possible scenario that, in reality, it has not had to address since the Second World War: the eventuality of a threat to its territory that it might have to deal with without resorting to the US or even NATO. For the EU to either deter this scenario or, perhaps, effectively face it, it will have to build a credible military capacity. The independence of this capacity from all non-EU factors is key. Otherwise, it will risk its functionality and it will increase the likelihood that it could be held hostage to external leverage, thus jeopardising the EU’s ability to implement its own decisions and protect its values and interests. For the above to materialise, strong political will is essential. The rationale behind the need for this political will should be found in the fundamental values on which the EU was historically constructed: intertwined peace and prosperity for all member states.
Introduction
If we wanted to capture in a nutshell the very essence of today’s EU defence situation and its future challenges, there is no more eloquent depiction than that of the first meeting between the newly elected US president, Donald Trump, and the president of Ukraine, Volodymyr Zelensky. The notion of strength versus that of values was imposed in the bluntest way during that conversation, as exemplified by the absence of ‘cards’ on the part of Zelensky. And, hence, on the part of the EU, which had insisted that Ukraine should be supported all the way in defending its territorial integrity. However, the EU has now been dragged into a process that is leading far from its fundamental goals and principles. And, together with it, Ukraine.
This was a shock for an EU that, since the end of the Second World War, has taken its security and peace, as well as the US’s catalytic involvement in guaranteeing these, for granted. And although wars have erupted on its periphery during that time, today the perception of a possible conventional threat against its very self is ringing the strongest alarm bells ever. All the more so, in the face of a US that is manifestly withdrawing from confronting Russia in Ukraine and has even exhibited signs of rapprochement with Moscow. A first assessment of this shocking realisation would downplay this as a temporary tendency, ascribed exclusively to Trump’s presidency. However, a more careful examination would demonstrate that the US urged Europeans to take more defence responsibility for their own continent as early as in the aftermath of the Second World War, and certainly in the aftermath of the Cold War. More notably, the ‘pivot to Asia’, which shifted US focus away from the European and Middle Eastern sphere, was a strategy of the Obama administration, adopted in 2011.
The truth is that, on many occasions since the end of the Second World War and, more imperatively, in the aftermath of the Cold War, Europeans have been faced with the challenge of building a reliable common military capability of their own for a high-intensity conflict. The key to their failure to do so has been the fact that, ultimately, they could still count on the US to provide the military capabilities they could not. Today, it is clearer than ever that those days are coming to an end and that, this time, it is crucial not only for the credibility of the EU, but also for existential reasons, that they deliver.
What the history of the Common Security and Defence Policy tells us
The vision of a European Defence Union goes back as far as the end of the Second World War. In the aftershock of two devastating world wars, the need to protect European states from conventional threats led to the first attempts at unification. The signing of the unsuccessful plan for a European Defence Community in May 1952, the establishment of the Western European Union in 1954 and the fruitless plan of the Fouchet Commission in 1961 were all steps in this direction. However, European military weakness compared to Soviet power, the need for European economic reconstruction and the lack of sufficient political cohesion did not allow for the implementation of a European solution.
The American commitment to the security of the European continent was thus essential, particularly in the light of the Cold War. The establishment of NATO institutionalised this reality. In this way, the US prevented the possible ‘Finlandisation’ of Europeans and ensured their allied stance. However, even this early, and with the war in Korea demonstrating the need for US involvement in other parts of the world too, American pressure on Europeans to assume greater responsibility for the defence of their continent could be observed. This pressure would also develop into the constant threat that NATO would be dissolved should Europeans not take on this responsibility (Howorth 2000, 10).
The end of the Soviet threat removed the direct and pressing need for an American presence in Europe and, with it, US tolerance. At the same time, the wars that then broke out on the EU’s periphery, in the former Yugoslavia and the Persian Gulf, established the complete inability of Europeans to defend their continent and their wider neighbourhood on their own. The war in Kosovo acted as a catalyst for the creation of what is now the Common Security and Defence Policy (CSDP) (Shepherd 2009). The risk of the US staying out of the game next time was visible, and pressure from the US Congress to increase burden-sharing intensified European concerns. Moreover, in Kosovo, Europeans realised the extent of their weaknesses on the battlefield, which also led to their limited role in strategic decision-making. The leading role of the US in operations gave the Americans such a sense of superiority that it even led politico-military circles in the US to question the system of unanimity in NATO, as they considered the American contribution to be disproportionately large compared to the one vote that the US had in decision-making (Evans 2000).
It is evident that no one in Europe can claim that there have not been any warnings about the situation we are in today. For almost 80 years, Europeans have known that they do not have the capacity to defend the security of their continent and its periphery on their own. And they have been urged by the US to prepare themselves to take on these responsibilities, as they have also been warned that there may come a day when they will be left alone to do so. In addition, they have been faced with the possibility of having to leave decisions about their own continent to be taken by Washington due to this inadequacy. However, the perception of the absence of a tangible conventional threat and the fact that the US would ultimately always get involved in hard times gave Europeans the luxury of believing that there was not really a need to do more than they were already doing, at least within the CSDP. The withdrawal of US involvement in Ukraine has made clear that the CSDP, as it is, is not enough.
The CSDP’s handicaps and the way forward
The CSDP faces inherent limitations. Such limitations include its fragmentation into member states and their heterogeneity, the lack of coherent leadership, the European deficit in military capabilities, and the priority given to economic and development policies within the EU. And yet, it is its relations with NATO and the US that are the major obstacle to its development.
The EU’s autonomy vis-à-vis NATO has perhaps been the most critical issue since the CSDP began to be shaped (Howorth 2003). Today, the CSDP is the product of negotiations between Europeanists, that is, those who have a more visionary approach to the EU’s place in the global system and who support Europe’s autonomy from the US, and Atlanticists, that is, those who have a more practical approach, favour the leading role of the US in European security and do not trust the prospect of developing an independent EU defence capability. Indicative of the obstacles to the development of the CSDP is also the fact that the US, despite its admonitions to Europeans to take more military responsibility, did not wish to jeopardise its own hegemonic role in transatlantic relations. And that is why the US opposed and undermined any attempts to make the CSDP autonomous. Thus, in all basic texts governing the formation of the CSDP, the need for close cooperation and coherence with NATO is emphasised. But most detrimental to the autonomy of the CSDP was the US insistence on avoiding overlaps between the two organisations and on the EU resorting to the use of NATO assets and capabilities and not creating its own autonomous ones to conduct operations. This insistence led to the so-called Berlin Plus agreement that stipulated the rules for the use of NATO’s assets and capabilities by the EU (Brenner 2002; Albright 1998).
However, this discussion took place in an era when the EU could only envisage its missions as being crisis-management operations of low intensity. But in the context of the war in Ukraine and the US threat to disentangle itself from it, the unthinkable has now become a possibility: the EU could be called upon to undertake a major operation on its periphery, and maybe even a collective defence operation, without the involvement of the US or even NATO (Lunday et al. 2025).
This is not an unlikely scenario. The case of Ukraine has now demonstrated, in the most emphatic way, the striking divergence of perceptions and approaches between the US and the EU. What is most alarming, though, is how the EU’s inadequacy in the field makes it unable to defend its principles and values, as well as its interests, and results in it acquiescing to US decisions that are far from aligned with its own perceptions and pursuits. At the same time, an overt lack of respect is being exhibited towards the EU, which is being excluded from discussions and decisions on issues of vital importance to its own continent. Consequently, the EU’s credibility is being damaged on the international scene and in the eyes of its citizens. Likewise, within NATO, the US’s hegemonic role may henceforth not allow the Alliance to adequately address European concerns, also in the light of the current divergence of opinions on Ukraine. Let us not forget that this possibility had already begun to emerge in the 2000s (Brzezinski 2009; Webber 2009; Flockhart and Kristensen 2008; Daalder and Goldgeiger 2006; Talbott 2002). The US’s different priorities may result in NATO forces being directed to support those and actions that are more important for Europeans being blocked. American intentions to transform NATO into a global security organisation and promote ‘global partnerships’ are indicative of this.
Thus it is crucial that the European Defence Union can rely on its own assets and capabilities, if necessary, and not depend on US and NATO ones. It has been argued that a constructive duplication could prove beneficial, both for the EU and the US, but also for the more effective conduct of operations (Schake 2001; 2002). For example, the case of the operation in Kosovo, where NATO essentially had to employ all of its rapid reaction forces and took up the full capacity of its headquarters, raises questions about the Euro-Atlantic ability to handle a second such crisis simultaneously (Silvestri 1999, 13). Furthermore, the Berlin Plus agreement entails that decisions on the availability of NATO assets for the conduct of EU operations are made on a case-by-case basis by the North Atlantic Council, so a veto is always possible. This would allow the US to either block operations to which it objects, or to prioritise those it considers more important. In the light of the diverging worldviews that have begun to emerge in Euro-Atlantic relations, such an action could not be ruled out, even in a collective defence case—that is, an attack on a NATO member state—if the US considered the defender to have ‘started the war’ or to ‘have no cards’. By the same token, the European Defence Union should avoid becoming dependent on NATO also because of other Allies that are not members of the EU. For example, Turkey could veto the use of NATO assets by the EU due to a dispute with the latter or with Greece and Cyprus (Gnesotto 2004, 109). In fact, during the negotiations on EU–NATO cooperation for the CSDP, which lasted almost two years due to Turkish objections, Ankara succeeded, among other things, in having Cyprus excluded from EU military operations conducted using NATO assets and, to this day, it requests the exclusion of Cyprus from all EU–NATO meetings, a fact that poses obstacles to cooperation between the two organisations.
But even in cases of an autonomous EU operation, while working together with like-minded non-EU partners is important, dependence on them for conducting operations or for armaments procurement, especially when their like-mindedness is questionable, could be suicidal. Again, the case of Turkey, about which there is a lot of talk, stands out. Turkey maintains a very low alignment rate (5%) with Common Foreign and Security Policy and CSDP statements and decisions (European Commission 2024, 82). Ankara does not participate in sanctions against Russia, but rather facilitates sanctions evasion, and has acquired Russian military systems that endanger Allied military technology. Moreover, it is difficult to imagine Turkey providing military assistance to an EU operation in which it would have to confront Russia in the field, such as a collective-defence operation. In addition, Ankara implements an interventionist policy in its wider region, in most cases by military means, permeated with a neo-Ottoman, revisionist ideology, while also promoting an Islamist agenda, as demonstrated by its support of Hamas, the Muslim Brotherhood and other radical movements, and its threats of war against Israel (Bozkurt 2025; Suryadnaya 2024; Schanzer 2025). The possibility of its participation in the ReArm Europe fund will result in EU resources being used to strengthen Turkey militarily against EU members Greece and Cyprus, and to support Ankara’s interventionist policy in the region, which is often contrary to Euro-Atlantic values and interests. Given its conflicting agenda with the EU on fundamental issues, Turkey’s contribution to the European Defence Union would grant it enormous leverage over the EU. An example of how Turkey uses every lever it has to put pressure on the EU is the failed attempt in 2020 by the Turkish state to pull off a massive migrant invasion at the Greek border, using thousands of migrants as a hybrid threat—a strategy that was later copied by Belarus (Tzimas 2021). Ankara also uses its Turkish and Islamist diaspora to meddle in EU member states’ domestic affairs and policies (Cornell 2017; Arab Weekly 2020). Finally, its democratic, rule of law and human rights records pose serious moral concerns. The Turkish veto in NATO, which was used as leverage over Sweden and Finland with regard to the extradition of Turkish dissidents from these countries, among other demands, points to serious dilemmas. It is, therefore, paradoxical that the European Defence Union should seek autonomy from the US only to become dependent on Turkey.
Hence, it is absolutely vital for the EU to acquire its own, completely autonomous, military tool if it wishes to be truly safe and protected.
The key parameter for the construction and use of this tool is unified political will. The rule of unanimity, but also the large number of EU member states, makes reaching a consensus on CSDP issues difficult. The particular perceptions in relation to what constitutes a threat; the particular interests, internal factors and histories of the member states; and also the differing aspirations regarding European integration and the relationships with the US and NATO affect the achievement of consensus. Proposals for decision-making reform are very difficult to implement as the CSDP touches upon core national interests, which, in some cases, are of vital importance. A possible relaxation of the unanimity rule could be more easily accepted by some member states if it were accompanied by automation in the imposition of consequences and sanctions against aggressors and by a system of binding security guarantees in the event that any state was subject to a military threat. Nonetheless, crucial for achieving consensus is the existence of a clearly defined threat. During the Cold War, the existence of such a threat also implied a certain automatism in terms of the response to it. For this reason, we will examine below the importance of an a-priori unified and clear perception of who or what constitutes a threat to the EU and requires an automatic response.
A values-based strategy
Political will is the key to the development of a European Defence Union, to assuming the cost for its autonomy and to the readiness to use it. Political will is always a complex matter in terms of EU mobilisation. In order to overcome this complexity, those elements that unite the member states and constitute their common goals, aspirations and imperatives must be brought to the fore, so that a common approach can be formulated as to the need for a European Defence Union and the conditions under which action will be taken. So far, such efforts have been made in various texts.
The Common Foreign and Security Policy sets among its objectives the safeguarding of the independence of the Union. The gradual development of a common defence policy was envisaged, which could eventually lead to a common defence. With the Treaty of Amsterdam, the safeguarding of the integrity of the EU was added, particularly concerning its external borders. The Treaty of Lisbon introduced a ‘mutual defence clause’ (Article 42(7) of the Treaty on European Union), which provides that, ‘if a Member State is the victim of armed aggression on its territory, the other Member States shall have towards it an obligation of aid and assistance by all the means in their power, in accordance with Article 51 of the United Nations Charter’, which concerns the right of states to self-defence.
Until the invasion of Ukraine, however, during a time when a conventional threat against a member state was considered unthinkable by most member states, the scope of the CSDP was essentially limited to Petersberg missions, that is, smaller crisis-management operations, on which consensus could be achieved more easily. As regards a mutual defence provision, the negotiations preceding the Lisbon Treaty divided the member states. Once again, the fixation on relying on NATO and US security guarantees deterred many member states from adopting a commitment similar to that of NATO’s Article 5, for fear of undermining the Alliance and transatlantic relations with an organisation that could not offer such guarantees. Yet, in the light of current developments, the issue of mutual defence is becoming key to the CSDP’s development and requires a different approach to be taken, especially given that neither US nor NATO assistance is at all guaranteed anymore. In this respect, the mutual defence clause that was eventually included in the Lisbon Treaty could provide the framework for meeting today’s demands. Also, the Strategic Compass for Security and Defence (Council of the EU 2022) called for mutual assistance and solidarity in the case of aggression against one of the member states. Considering these texts and as a matter of credibility, deterrence and, ultimately, survival, it therefore seems inescapable that the EU becomes able to react militarily, within NATO or outside of NATO, should a military threat arise at its borders.
As regards a common threat assessment, the White Paper for European Defence (European Commission 2025) singles out Russia. It also stresses the importance of the defence of all EU land, air and maritime borders, but again it singles out the eastern border. Nevertheless, looking at the EU’s south-eastern border, we should also take into account that another front has been underestimated; while identifying Russia’s revisionist and aggressive character, it is contradictory not to recognise the same characteristics in Turkey. Turkey occupies 37% of EU member state Cyprus; it constantly threatens EU member state Greece with war, most notably should Greece exercise its right to extend its territorial waters in accordance with the UN Convention on the Law of the Sea (a threat also officially stated by a Declaration of the Turkish Parliament); it claims 152 Greek islands to be Turkish, contrary to the relevant treaties; it demands the demilitarisation of 23 Greek islands, disputing Greece’s sovereignty if it does not comply; and it has officially adopted the expansionist Blue Homeland doctrine, claiming half of the Aegean Sea and almost all of Greece’s and Cyprus’s Exclusive Economic Zone in the Eastern Mediterranean. It also persistently advertises its historical rights and zones of influence in the wider region.
But, at the end of the day, the EU should take action based on the lowest common denominator, its values. The EU has traditionally been perceived as a values-based power. Its success and the power of its attraction derive from the fact that it is a unique model in history constructed upon values-based reasoning: the ideal of a pacified European continent, where war would henceforth become inconceivable. And yet the idea of it being based upon values was not utopian. What makes this endeavour a remarkable case in point was not the absence of interests in its construction, but the mobilisation of those interests to serve values, and thus the creation of interwoven interests among the member states that consolidated solidarity (Skordeli 2012).
Hence, in the search for the political will to enhance and mobilise EU defence, the key is this values-based paradigm. Member states should always keep in mind that peace and prosperity within the EU have become intertwined among the member states and that it is as a result of this that they have become possible. So, despite the distance of a member state from a threat or its individual interests, peace and prosperity within the EU are indivisible. And therefore, in a world that is becoming dominated by power politics, transactionalism and challenges to the inviolability of borders, the EU’s answer can only be ‘values’, such as the core values that dictated its establishment—notably international law, non-aggression, independence, territorial integrity and solidarity. ‘Values’ should apply to threats against all member states, without double standards, as otherwise the EU’s deterrence and credibility as to its defence of values will be equally compromised.
Conclusion
Today, the key issue for EU defence has become its ability to defend the Union’s territorial integrity. It has become apparent that EU dependence on the US and NATO for its security may no longer be an option, even if it wanted to remain dependent. It is, therefore, critical that the Union develops its own military capacity independent of all external dependencies that could compromise its actions and values. For the above to happen, strong political will is required. Historically, the EU has become a success by responding to great challenges with values-based reasoning, which has created common interests in solidarity. Values should thus remain the guide in the search for the political will to advance and mobilise EU defence.