© Claude Truong-Ngoc / Wikimedia Commons

Written by Guido Lanfranchi


“By the present Treaty the High Contracting Parties institute among themselves a European Defence Community, supranational in character, consisting of common institutions, common armed Forces and a common budget.” (European Defense Community, 1952). A reader who is relatively unfamiliar with the history of the European Union (EU) might wonder where this excerpt comes from. It may be a science fiction novel, or maybe a treaty to be signed around the year 2050. These are surely legitimate answers, but they are incorrect. This text is Article 1 of the Treaty Constituting the European Defence Community (EDC), signed by Germany, France, Italy, and the Benelux countries in 1952. Contrary to the expectations of the signing parties, the French Parliament refused to ratify the Treaty two years later thus burying the EDC project. Nevertheless, the European integration process continued and as time passed European states felt an increasing need to coordinate on matters related to foreign and security policy. Defence policies are currently a key component of foreign and security policies, and they are therefore a crucial determinant of Europe’s stance at the global level. Knowing this, over the last decades European states have repeatedly tried to enhance their cooperation in the defence field, although with limited success. Yet, pushes in this direction continue to this day, making the following question all the more relevant: what is the most suitable approach to enhance defence cooperation at the European level? 

This paper will address this question by first exploring the existing literature on European defence cooperation, and then proposing tentative solutions to further such endeavour. In the first section, this paper will introduce the case of European defence cooperation and its complexities. The second section will outline the main theoretical accounts on the decision-making process underpinning the European defence policy. The third section will then use a combination of theoretical and practical insights in order to propose a framework solution that could enhance European defence cooperation. Starting from this framework, the fourth section will suggest some proposals, evaluating their consequences, strengths, and weaknesses. The last section will summarise and conclude the paper. 

European defence policy: current debates for an old issue

Since the concluding phase of World War II, the issue of European defence policy has been pivotal for policymakers in Europe and beyond (Gegout, 2010, pp. 5-9). In the aftermath of the war, fear of renewed German aggression and a desire to stabilise the continent prompted France, the United Kingdom (UK), and the Benelux countries to establish the Western Union (WU) – the first prototype of a defence alliance in the European continent. In the early 1950s, however, as the United States (US) intensified its calls for West Germany’s rearmament in anti-Soviet function, European diplomats started working on a more ambitious plan. The new project – named “European Defence Community” (EDC) – envisioned a tight European military alliance, intended to include France, the Benelux countries, Italy, as well as West Germany. In spite of the signing of the EDC Treaty in 1952, however, the proposal was stopped in 1954 by the French Parliament, and European diplomats were forced to reduce their ambitions. The WU evolved into the Western European Union (WEU), which included Italy and West Germany, albeit with diluted commitments. While the WEU remained for some time the cornerstone of European defence cooperation, efforts in the field of foreign policy coordination proceeded in parallel, with the establishment of the European Political Cooperation (EPC) in 1970 and the Common Foreign and Security Policy (CFSP) in 1993. In the CFSP framework, the year 1999 witnessed the establishment of the European Security and Defence Policy (ESDP), which evolved into its current form, the Common Security and Defence Policy (CSDP), in 2009 with the Treaty of Lisbon.

After such a long history of attempts at integrating European defence policies, results are currently still modest, and defence competences still mostly lie at the state level. Yet, new attempts at further cooperation continue today, with the EU institutions and the leaders of some major EU countries calling for more integration of EU defence mechanisms (Marrone and Ungaro, 2014; De la Baume and Herszenhorn, 2018). Why is there so much insistence on this issue? The reason lies in Europe’s continued, and arguably increasing, will to play a role at the global level (EEAS, 2016; EEAS, 2019). In order for its foreign policy to be effective, any international actor is generally better served by a combination of different tools (Nye, 2009). Over the decades, the European Union has developed good “soft power” tools, as their values and policies have earned a generally good reputation globally. Also, they have developed other “mixed” tools that are instrumental for wielding power, such as EU trade policies through which member states speak with a single voice. However, on “hard” power tools, and especially on military issues, the coordination among EU countries remains rather loose (Gegout, 2010, pp. 56-57, 62; Vai, 2017, pp. 194-195; Zandee, 2017, p. 2). While the lack of a common European armed force is the most evident aspect of this phenomenon, cooperation is relatively weak also on smaller issues, such as intelligence sharing, provision of military equipment, as well as logistics and troops transportation (Ibid.). Therefore, defence cooperation persists as a matter that the EU has to address if it wants to pursue its ambitions as a global player.

Over the decades, scholars have written a significant amount of literature on European defence cooperation. Some have focused on analysing the developments of foreign policy and defence cooperation at the European level (Guay, 1996; Glarbo, 1999; Jones, 2006; Gegout, 2010; Devuyst, 2012; Piechowicz, 2015; Zandee et al., 2016; Dijkstra and Vanhoonacker, 2017; Drent and Zandee, 2017; Vai, 2017). Others have focused more on future scenarios, envisioning incipient dynamics (Jones, 2011; Howorth, 2012), or advocating for new initiatives (James, 2005; Biscop, 2017; Zandee, 2017). This paper will draw on the analyses present in literature, and use these insights in order to propose a tentative framework solution to the long-standing problem of European defence cooperation. The next section will thus provide an overview of the different analyses concerning European defence cooperation, focusing specifically on decision-making processes.

Decision-making processes in European defence policy

While integration in fields such as monetary policy and trade has been outstandingly deep in the EU, Member States (MSs) have generally been reluctant to relinquish their sovereignty on foreign and defence policies (Gegout, 2010, pp. 3-4; Devuyst, 2012, pp. 328-331; Vai, 2017, p. 192). As a result, these policies are at present still in the hands of single MSs or, at most, of the European Council. The Council has a pivotal role in defining the EU foreign policy, as its tasks include: identifying the strategic interests and objectives of the EU external actions; defining the guidelines and the decision in the framework of CFSP and CSDP; and assessing the threats faced by the Union (Gegout, 2010, pp. 45-46, 48; Devuyst, 2012, pp. 330). However, since unanimity among MSs is required to take any major decisions at the Council level, the EU foreign policy making process has often been stalled due to diverging interests among the MSs (Gegout, 2010, pp. 44-46, 63-64; Devuyst, 2012, pp. 328-331; Piechowicz, 2015, p. 549). 

Even if the Council formally retains the ultimate power on foreign and defence policymaking, other European institutions will continue to play a relevant role too. For instance, the European Parliament exercises control over the EU budget, and it has the right to make parliamentary inquiries concerning initiatives by other institutions (Dijkstra and Vanhoonacker, 2017, pp. 11-12). Therefore, in spite of its relatively weak position concerning foreign policy issues, the Parliament has some tools to at least control the developments through these means. The role of the European Commission is more significant, as its broad competences are often necessary in the implementation of foreign policy strategies (Dijkstra and Vanhoonacker, 2017, pp. 11-12). For instance, if the Council decides to enforce certain economic sanctions as part of a foreign policy strategy, the implementation of this decision will have to involve the Commission, which is responsible for economic and trade policies. Moreover, it should be noted that since the launch of the 2016 European Defence Action Plan (EDAP) the Commission is set to play an increasingly relevant role, especially through the provision of communitarian defence funding in the framework of the European Defence Fund (EDF) (Zandee, 2016; Drent and Zandee, 2017, pp. 3, 5, 9-10).

The interaction between states-centred institutions (the Council) and community-centred ones (the Commission and the Parliament) in shaping foreign and defence policy has sparked a lively academic debate on the nature of EU decision-making in these policy areas. Intergovernmentalism is arguably the most widespread interpretation of EU foreign policy making. According to this perspective, which significantly draws on Moravcsik’s (1998) account of EU integration, states are the central actors in the EU integration process, and all the more so in sensitive fields such as foreign and defence policies (e.g. Devuyst, 2012, pp. 328-331). By contrast, sociological institutionalism presents quite a different account of EU foreign policymaking. According to this theory, which is largely based on constructivist perspectives, states are still relevant, but their behaviour and interests are deeply influenced by socialisation processes that are beyond their control (e.g. Glarbo, 1999).

The intergovernmental and the sociological institutional views have often been presented as alternative views. However, an increasing number of scholars have tried to somehow reconcile the two, attempting to maximise their theoretical explanatory power (Gegout, 2010, pp. 176-195; Howorth, 2012; Piechowicz, 2015, pp. 549-550; Dijkstra and Vanhoonacker, 2017, pp. 9-13; Vai, 2017, pp. 193-194). In doing so, these authors have created new hybrid theories, such as “constrained intergovernmentalism” (Gegout, 2010), “supranational intergovernmentalism” (Howorth, 2012), and “intensive transgovernmentalism” (Dijkstra and Vanhoonacker, 2017). These accounts are largely based on intergovernmentalist assumptions. However, they also incorporate useful insights from sociological institutionalism as well as other relevant International Relations theories. This paper subscribes to these more nuanced views, and in particular to Dijkstra’s and Vanhoonacker’s (2017, pp. 9-16) account of the EU´s foreign policy making structure as a “multi-layered” one, combining “coordination between the member states” and “delegation of functions to the EU institutions.” 

A framework solution for European defence cooperation

The first section of this article has shown the relevance of European cooperation on foreign and defence policy. However, as the second sections has highlighted, this cooperation is still largely intergovernmental by nature. Given the aforementioned traditional reluctance of states to pool sovereignty on sensitive issues such as foreign and defence policy, the lack of deeper European integration in these policy areas is (at least partly) explained. In the light of these observations, it is thus all the more important to analyse this paper’s fundamental question: what is the most suitable approach to enhance defence cooperation at the European level? While exploring answers to this question, another theoretical tradition can be of help: neofunctionalism. Neofunctionalism traces back to Haas’ (1958) work on European integration at large. As explained by Guay (1996, pp. 408-411), the focus of this theory is the concept of “spillover.” According to this concept, integration in one area gradually leads to further integration in other areas, on account of functional, political, and cultivated contagion-like dynamics. Building on this theory, Guay (1996, pp. 411-416) developed the concept of “reactive spillover.” This concept acknowledges the spillover dynamics, but it also considers the role of the international environment, which can explain the historically irregular pace of EU integration, thus nullifying the main criticisms of neofunctionalist theories. This essay subscribes to this view, particularly on account of the power that (reactive) neofunctionalism seems to have in explaining the EU’s success in pursuing a deep economic integration and guaranteeing more than 70 years of peace in Europe. 

Following the neofunctionalist logic, this essay argues that the most suitable approach to enhance defence cooperation at the European level is through a ‘bottom-up’ approach. This strategy entails the establishment of different low-level cooperations among different groups of states brought together according to different convergence criteria. As Zandee (2017, p. 5) stresses, “it is time to stop pursuing the impossible,” that is, the top-down, rapid establishment of a cohesive EU defence structure, through which all MSs can pursue their whole spectrum of interests. Rather, the focus – at least in the short-term – should be on a differentiated integration à la carte, in which MSs can pick and choose the initiatives to which they participate (Vai, 2017, p. 207). Therefore, (short-term) efforts should not aim at a unified grand strategy defined on paper by top-level officials of all MSs. Rather, cooperation should be manifold, and it should start at the scale of low-level military units, given that bottom-up initiatives are usually more stable than top-down ones (Zandee et al., 2017, p. 5). Consequently, cooperation should not necessarily involve all states, all at once. Rather, states should be able to join different groups according to their will. Crucially, these different groups of states could be formed according to various criteria, including for instance geographic proximity, shared foreign policy interests, or complementarity of capabilities. As for the long-term, the neofunctionalist logic would then suggest that cooperation, if properly managed, could likely lead to deeper collaboration in the future among an increasing number of MSs, on an increasing number of issues and at an increasingly high level.

In spite of the appealing nature of this proposal, such a strategy surely entails some dangers. The most critical scenario is the crystallisation of the à la carte formula, with the ensuing risk of permanent divisions among MSs (“cantonisation” of European integration) or, even more radically, the implosion of the European integration process. As Vai (2017, p. 207) notes, there is a possibility that “the neo-functionalist driving force that fostered a closer integration for years has begun to run out.” If this is the case, the aforementioned risk of integration failure would be even greater. It is therefore worth to clarify how European policymakers could minimise the likelihood of this negative scenario to materialise. According to this paper, the most effective countermeasure lies in the diversification and the interweaving of the different cooperation instances. For instance, if groups are formed on a single criterion, the risk of cantonisation along this fault line could be rather high. Blocs of countries could cement their internal ties, but this process would risk reinforcing the divergences between different blocs – somehow “crystallising” inter-blocs divisions. Using multiple criteria as the basis for grouping countries would prevent this crystallisation process. In such a scenario, countries would group together along multiple fault lines, creating a criss-cross pattern of shifting alliances. For instance, countries belonging to different blocs on account of their position on a specific foreign policy issue might find themselves aligned on another. Additionally, they might collaborate in another group of countries due to their complementary capabilities. Such a fluid arrangement would arguably prevent the formation of fixed blocs, thus dramatically reducing the risk of cantonisation. Moreover, the establishment of different cooperation instances could help mitigate the risks ensuing from failures in the integration process. In the context of a monolithic integration process aimed at reconciling the interests of all states on all issues, any failure would likely affect the process as a whole. To the contrary, in the context of a fluid, multi-pronged integration process, failures could take place at a lower scale. Unsuccessful experiments of cooperation could then simply be discarded by states and put aside, without significantly compromising progress on other cooperation instances. In light of the advantages outlined in this section, this paper advocates for an integration strategy that entails different cooperation instances, among different groups of states, formed according to different criteria.

Practical proposals and their consequences

Up to this point, this essay has argued that the ‘bottom-up cooperations’ strategy is the most suitable approach to enhance European defence cooperation. The aim of this section is then to lay out some practical proposals on how to implement such a strategy. The focus here will be on two specific case studies: operational cooperation and defence industry cooperation.

Operational military cooperation

Bottom-up operational military cooperation is intended as a structured cooperation between relatively small military units (e.g. at the level of companies, battalions, or brigades). Some examples of this kind of military cooperation are already in place at the European level. Among them, one can find the Eurocorps, the Franco-German Brigade, the UK/NL Landing Force, the Franco-British Combined Joint Expeditionary Force, the 1st German-Netherlands Army Corps (Munster), the German-Polish Multinational Corps Northeast (Szczecin), the European Air Transport Command (Eindhoven), as well as the integration of Dutch, Czech, and Romanian brigades into the German Army (Jones, 2011; Zandee et al., 2016; NATO, 2017; BBC, 2018). 

These experiments provide an undoubtedly positive basis for the strategy advocated by this paper. Yet, more should be done in terms of scale – that is, increasing the number of cooperation instances – as well as in terms of depth – that is, promoting progressively tighter cooperation among states in each instance. Constant assessments of different integration experiments could help policymakers adjusting the strategy over time, notably by discarding or modifying unsuccessful experiments, while replicating and expanding successful ones. Moreover, research has shown that this kind of cooperation efforts can be more successful in the presence of certain conditions, such as for instance trust, solidarity, realism, clarity, seriousness of intentions, and low/null costs (Zandee et al., 2016, pp. 3-7, 55-60). These insights could surely help policymakers in selecting the most promising projects, thus further enhancing the chances of success enjoyed by this strategy.

In light of these observations, the cooperation experiments outlined above might well prove instrumental in shaping the future of European defence integration. Adopting such a forward-looking perspective, for instance, the Lancaster House Treaties of 2010 between the UK and France might not be seen as a snobbish bilateral effort, but rather as a potential future gold standard for further integration experiments, or even as a pole of attraction for others to join (Jones, 2011, pp. 37-45). Going further in this direction, some authors argue in favour of bringing the operational cooperation logic to an even wider scale. For instance, Zandee (2017) advocates for a model of European defence as a network of interoperable, interconnected “core groups” based on capability and will. Noting that defence priorities and interests are still set at the national (or, at best, small-regional) scale, Zandee proposes that core groups of countries should deal with tasks in which they are specialised and interested, relying on the network of other partner states for the performance of other tasks. Such scenarios are indeed appealing, and even more so in the light of the neofunctionalist logic: if the spillover effect would actually materialise, such scenarios might well be the precursors of a deeper, more cohesive European defence integration.

Defence industry cooperation

Defence industry cooperation is intended as the cross-border involvement of governments and companies in joint projects of, respectively, procurement and development of military capabilities. This is a rather old phenomenon, already widely noticeable by the mid-1990s, as European defence companies started to exploit the advantages of the single market (Guay, 1996). In the 2000s, the trend continued, with governments undertaking efforts towards enhanced collaboration in military procurement (e.g. Taverna and Sparaco, 2004), and academics proposing closer European cooperation in the development of new military capabilities (James, 2005). By the mid-2000s, enhanced defence industry cooperation had already generated positive results, such as the development of the Eurofighter project (since 1983), the creation of the European Defence Agency (EDF, since 2004), and the establishment of a series of globally competitive European defence companies (e.g. BAE Systems, Thales, EADS, and Finmeccanica, which by 2005 were among the 10 top defence companies in the world) (Jones, 2006, p. 241, 255-266; Jones, 2011, p. 43). Finally, the recently launched EDAP, if properly managed, has the potential of giving another boost to European defence industry cooperation, especially thanks to the funding provided via the EDF (Drent and Zandee, 2017).

Two observations are in order on defence industry cooperation. First, it is evident that European cooperation in defence industry has gone far beyond cooperation on the military operational level. Arguably, this is the results of the fact that the defence industry is run as a business, and as such it has been able to reap the benefits of the single European market since the 1990s. Second, one might argue that joint partnerships have been enabled by European regulations or lack thereof, thus constituting a top-down approach, which would be inconsistent with the approach advocated in the present paper. This observation is true, in the sense that regulations have indeed been established at the European level. Nevertheless, it should be noted that these regulations have not artificially created defence behemoths. Rather, they have simply enabled the development of joint, cross-border initiatives from European companies of different scales, that is, they have fostered a bottom-up approach to European defence industry cooperation.

Recent EU initiatives

In recent times, the EU has launched very interesting initiatives on both the military operational level and the defence industry one. For instance, in the 2016 European Defence Action Plan framework, the EDF makes funds available through two windows (Zandee, 2016; Drent and Zandee, 2017). On the one hand, the research window will finance joint cross-border research projects, thus boosting cooperation at the defence industry level. On the other hand, the capability window will help MSs in the procurement of capabilities developed in the joint projects, thus boosting cooperation both at the military operational level (by ensuring the use of the same systems across armies) and at the defence industry one (by ensuring purchases of the jointly developed capabilities).

Even more recently, the European External Action Service (EEAS) has launched the so-called Permanent Structured Cooperation (European Council, 2018). PESCO is outstandingly similar to the strategy advocated in the present paper. The participation of the MSs is entirely voluntary, and the decision-making power remains in the hands of the MSs that decide to participate. Moreover, each MS can decide which of the jointly defined projects it wants to participate in, then collaborating to its development with other willing MSs. The 17 initial projects encompass a broad spectrum of issues, including the military operational domain, as well as the development of shared capabilities through joint industrial efforts. Moreover, these projects will be able to benefit from the financial support provided via the EDF. The recent European efforts, therefore, seem to be well-directed, as they are aimed at providing a favourable environment for voluntary, specific, diverse, modular cooperations. Concerning future developments, time will tell whether the spillover approach will work for the sensitive issues of foreign and defence policy too.


In a rapidly evolving regional and international environment, any attempt to predict future developments in the field of European defence cooperation would be little more than guessing. The UK’s exit from the EU and the unilateralism that characterises the current US’ administration are exercising a wide set of different strains on the European integration process. Nevertheless, the recent measures taken by the EU on foreign and defence cooperation seem to allow for some optimism. This paper analysed the long-standing question of how to suitably enhance defence cooperation at the European level. The initial section of this paper has shown that, if the EU wants to play a relevant role globally, it needs a common foreign policy, of which a common defence policy is a pivotal part. It evaluated the European decision-making process on foreign and defence policy issues, concluding that this process’ nature is, at least formally, largely intergovernmental, even if communitarian tendencies do play a role too. Then, this paper introduced the neofunctionalist concept of spillover, which has been used as a basis for developing a framework solution for European defence cooperation: the ‘bottom-up cooperations’ approach. This approach calls for the establishment of different low-level cooperations, among different groups of states, brought together according to different convergence criteria. In the last section, this paper provided two potential implementations of the proposed approach, specifically in the fields of operational military cooperation and defence industry cooperation. Finally, the paper has reviewed the most recent EU initiatives on CFSP and CSDP, concluding that the combination of the EDAP and the PESCO seem to point in the right direction for European defence integration. Dear spillover, please do not let us down

Guido Lanfranchi is currently a master’s student in International Security at Sciences Po Paris, as well as a reporter and associate editor for Diplomat Magazine The Netherlands, a Dutch diplomatic magazine. After graduating in Biomedical Engineering from Politecnico di Milano, Guido decided to switch to the field of international relations. He pursued a BA in International Studies at Leiden University, specializing in the Middle East and interning for five months at the Council of the European Union in Brussels. He is now continuing his academic career in Paris. Guido’s main interests include conflict issues, mediation, as well as the economic dynamics related to war and peace. 


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