Analysing shared competences in EU external action: the case for a politico-legal framework

2.1 A clear legal framework?

In legal scholarship on EU external action, the notion of competences is key. The nuanced approach to competences, and in particular to shared competences, as developed in legal doctrine is hardly visible in political science studies on similar topics, irrespective of the explanatory value of this nuanced approach. Among lawyers it is a truism that, as a legal principle, the EU only has the competences conferred upon it by the Treaties.¹⁴ In an ‘ever closer union’ the EU and its Member States share competences on nearly every issue of European political life, as the competences that are exclusively in the hands of the Union are limited.¹⁵ The Treaties contain a quite precise catalogue of competences spelling out the different types of EU competences:¹⁶

• exclusive competences, where only the Union has legislative power; ¹⁷

• shared competences, where both the Union and the Member States have legislative power; ¹⁸ and

• supportive competences, where the Union can support, coordinate or supplement the actions of Member States, but cannot supersede the competence of Member States in that policy area. ¹⁹

Competences in the area of the common foreign, security and defence policy are not further defined, apart from the acknowledgement that the Union does enjoy a competence in that area.²⁰ Yet, the Treaty context makes clear that competences in this area are shared between the Union and its Member States, allowing them – at least to a certain extent – to act in parallel.²¹

At the same time, practice reveals that, in relation to shared competences in particular, it remains difficult to define the exact division of competences between the EU and its Member States. Part of the problem is that ‘shared competences’ is a broad category and it is particularly the nuances that may also be helpful for political science studies to allow for a better understanding of the different situations of EU external performance. Four sub-categories of shared competences have been said to provide a more nuanced picture of the possible competence divisions between the EU and its Member States.²² The first category contains shared pre-emptive competences, where Member State action is only excluded if the EU has already taken action on the issue. Second, in the case of shared non-pre-emptive competences Member State action is not excluded as long as the EU has not fully deployed a policy field. Third, shared competences in case of minimum Union standards are identified, where Member States can adopt more stringent measures. Fourth, as we have seen, shared competence in the field of foreign and security policy can perhaps best be categorized as ‘parallel’ competences. We believe that for an analytical framework it is important to differentiate between these different sub-categories as they may all – in their own way – have an impact on the performance of the EU and its Member States in international institutions, in particular since they restrain Member State action in different ways.

With a view to the present article’s aim to assess the functioning of shared competences in the context of international organizations and conferences, it is important to recall that these days, several EU Treaty provisions provide a solid basis for the Union to establish a formal and substantive presence in international organizations.²³ This has certainly strengthened the EU’s ‘international actorness’ and confirms the separate legal status of the EU alongside its Member States.²⁴ Whereas in political science scholarship the distinction between the Union and its members is seen as less relevant (references to the ‘EU28’ or earlier to the ‘EU15’ often simply intend to point to the ‘block’ of EU institutions and Member States), from a legal perspective the distinction between the European Union as an international organization of which states can be members, and the (Member) States themselves remains essential.

A consolidation of external policies was clearly foreseen by the Lisbon Treaty, which, as held by some observers, now ‘makes Brussels the “key locus” of European external action’.²⁵ Yet the above-mentioned unclear external division of competences has led legal scholars to regard the external relations codification of the Lisbon Treaty as ‘rather unsatisfactory’ or they stress its ‘fuzziness’.²⁶ Authors even expressed the opinion that the Lisbon Treaty ‘failed in external competences’ as there is a need to resort to decades of pre-Lisbon case law from the CJEU to establish whether Member States are ‘pre-empted’ to act externally, meaning that their traditional international competences are restrained because of EU policies or initiatives.²⁷ The fluidity of competences in external relations has ‘provided a fertile field for ingenious legal argument’ over the interpretation of the Treaties before and after the Lisbon Treaty and the extensive case law of the CJEU on external relations only testifies to that.²⁸ At the same time, a lack of legal clarity offers room for political flexibility.

The final adjudicator of the use of competences in the EU is the CJEU. While for EU external relations lawyers the CJEU has been the central institution, it has often been overlooked by political scientists. In a way, the CJEU may seem to have been helpful in relation to the participation of the EU in international institutions as a means to exercise its competence.²⁹

At the same time, the CJEU’s case law also underlines that the division of competences is not clear-cut and that lawyers may not always provide a priori answers. Thus, we have seen that there are external effects of an internal use of competences by the EU: Member States may be barred from entering international agreements or international negotiations by themselves as some elements may fall within the ( de facto exclusive) competences of the Union.³⁰ And, on more than one occasion, the CJEU has used the ‘principle of sincere cooperation’ to point out that Member States are no longer completely free to engage in international activities.³¹ The controversies reflected in the recent and pending cases on the scope of the EU’s external competences, referred to in the Introduction to this paper, only testify to the idea that issues are far from settled, again leaving scope for political interpretations and an influence of findings in political studies.

2.2 A political perspective: EU actorness, cohesiveness and effectiveness

Indeed, the absence of legal clarity often leads to a (perceived) political flexibility. The concepts of actorness, cohesiveness and effectiveness traditionally drive the political theoretical perspective on EU external action, and we will shortly address all three concepts with a view to recent and ongoing debates on this in the relevant literature. There is a vast literature on the EU as an ‘effective’ actor in international institutions. This strand of literature focuses especially on more clear-cut EU-led or instead Member State-led policy areas, respectively global economic governance and Common Foreign and Security Policy.³² This may explain the absence (to a large extent) of approaches dealing with the sharing of competences. This does not mean that the relationship between the Union and its Member States has as such not been the subject of political studies. The debates between scholars that see the Member States as the primary driving force of EU integration (intergovernmentalism) and those that claim that it is in particular supranational agents that are pushing the integration process forward (supranationalism) are well known and remain the source of the ‘most important and persistent schism in the EU integration literature’.³³

The actorness literature is particularly relevant in our context as it shows clear references to legal competences, albeit that the main focus is on more ‘informal’ strategies and actions and ‘effectiveness’ of EU external action than on formal competences.³⁴ A landmark article on actor capacity is written by Jupille and Caporaso, who identify four dimensions of actorness: authority, autonomy, external recognition and internal cohesiveness.³⁵ Authority refers to the extent of delegated competences from the Member States to the EU, which ‘can take many different shapes and varies greatly by policy area’.³⁶ The delegation of authority can be formal, resulting from Treaty articles, or it can be informal, resulting from spill-over in practice. This way of seeing authority operating ‘beyond competences’ is echoed by more scholars. Vanhoonacker and Pomorska argue that important sources of authority are ‘not only the legal competences of an actor but also the expertise in a particular issue’.³⁷

The second dimension of actor capacity is ‘autonomy’, which refers to the institutional distinctiveness and independence of an actor from other actors.³⁸ An international organization like the EU should have ‘a distinctive institutional apparatus, even if it is grounded in, or intermingles with, domestic political institutions’.³⁹ The ‘autonomy’ concept, which is also visible in many legal studies,⁴⁰ is also evident in the principal-agent theory in which the ‘agent’ (mostly the European Commission) is able to make decisions and negotiate on behalf of the principal(s), the Member States. Therefore, in the principal-agent institutionalist theory approach, the EU is recognized as a separate, (partly) autonomous actor and could also pursue its own interests in world politics.⁴¹ Until now, principal-agent theory has been essentially used in policy domains with exclusive EU competences such as trade policy.⁴² Furthermore, principal-agent theory seems more oriented towards internal control mechanisms than enabling cooperation towards external actors. Opportunities are especially seen in the external context, not internally.⁴³

The third dimension of actorness is the recognition by others. It is seen as ‘the sine qua non of global actorhood’, understood as acceptance of and interaction with the entity by others.⁴⁴ The legal dimension is clear because recognition can be de jure and de facto. De jure recognition is seen as diplomatic recognition under diplomatic law and formal membership of international organizations. De facto recognition of the EU is given whenever third parties decide to interact with the EU and thus implicitly recognize it as an international actor.⁴⁵ Similar to ‘authority’, recognition is thus based on both formal and informal notions.

The fourth dimension of actor capacity, internal cohesiveness, is related to the well-known debate on a ‘single voice’ of the EU and the Member States and the related effectiveness. It entails that Member States neither undermine nor overrule the collective position to be defended with a single voice, even if they disagree with it.⁴⁶ Cohesiveness is an even more demanding concept than ‘one voice’ because it requires the authority of such voice, external recognition and autonomy from Member States⁴⁷ and follows a logical sequential order with these other dimensions.⁴⁸ Recently, however, this has become subject to debate in political science. Some even ask the question whether a common position is necessary at all for the EU to be an effective actor.⁴⁹ With this in mind, cohesiveness might even ‘diminish the EU’s bargaining power, efficiency and flexibility’.⁵⁰ Earlier political literature already suggests that a certain disunity can occasionally be a source of strength, used as a bargaining chip in international negotiations.⁵¹ For the purpose of the present article, it is worthwhile to note that the operationalization of the concept of cohesiveness is very much driven by formal competences. Da Conceição-Heldt and Meunier, for example, choose to simply use the formal rules of decision-making to operationalize the concept of internal cohesiveness, which means that internal cohesiveness is highest in the case of ‘exclusive competences’ and ‘medium’ in case of shared competences.

The ‘single voice’ debate is also visible in the growing literature on effectiveness where the EU is seen as a (collective) actor. ‘Common wisdom’ suggests that the higher the cohesiveness the higher the effectiveness, but a variety of policy areas suggests that the relationship, if it exists, is more complex.⁵² External effectiveness refers to the actors’ ability to realize the goals they set for themselves.⁵³ The concept of effectiveness traditionally assumes a positive and direct correlation between the degree of internal cohesiveness and the EU’s external effectiveness.⁵⁴ Recently, however, a second wave of scholarship has actively started to question the causal link between actorness, cohesiveness and effectiveness, most likely due to the ineffectiveness of EU external action since the Lisbon Treaty.⁵⁵

Like cohesiveness, effectiveness is increasingly seen not as a binary measure but as a continuum. As held by Niemann and Bretherton, effectiveness has historically been ‘notoriously difficult to analyse and assess’.⁵⁶ This has largely to do with the fact that the concept of effectiveness has traditionally been equated with goal achievement. Recent contributions have been looking more closely at the input and process side instead of ‘only’ the outcomes.⁵⁷ Oberthür and Groen already see a scope for further investigating their assessment framework of effectiveness components by embedding it in a broader explanatory framework including ‘additional’ internal factors such as mixity of competences, coordination arrangements under the Lisbon Treaty and the external institutional context.⁵⁸ This conceptual framework could also serve as a basis for a broader comparative research programme across policy fields.⁵⁹ Earlier, also Van Schaik (2013) expected EU competence to substantially affect the Union’s actorness and effectiveness in negotiations, while paying attention to the international negotiating context.⁶⁰

2.3 Confronting legal and political theories

Our brief overview of the prevailing legal and political insights into the EU’s potential to act globally alongside its Member States underlines what some others have found before: while legal and political theories on EU and Member State actors in international negotiations contain insights that are mutually helpful for both disciplines, they are hardly confronted or combined.⁶¹ While this generalization does not do justice to studies using a more ‘law in context’ approach, mainstream legal scholars do have a tendency to focus on ‘formal’ Treaty provisions and on case law with a view of establishing the correct division of competences between the EU and its Member States or between the institutions.⁶² Political theories, while even less generalizable, are more oriented towards power and less towards the legal competence behind this power. And, as we all occasionally experience, it is indeed difficult for one academic discipline to contribute to debates in the other. Interdisciplinary academic workshops not infrequently underline that lawyers and political scientists simply raise and study different questions, despite the fact that the overall answer they are looking for may be similar.

Indeed, as underlined by our short literature overview, the different disciplinary perspectives remain obvious. Where formalities are a key element in legal studies, they are far less important in a political perspective. The essence of an empirical analysis is more on ‘informal’ strategies and action. In addition to the formal rules on decision-making and representation, analysts ‘need to consider the informal behaviour of actors when determining the degree of internal cohesiveness of the EU in a particular external setting’.⁶³ Some even state in this regard that the formal status ‘plays an inferior role’ in actor capability.⁶⁴

At the same time, our short analysis of the debates on actorness, cohesiveness and effectiveness reveals the sometimes invisible links between the various approaches, especially in more ‘institutionalist’ political theories. In analysing EU actorness and cohesiveness, the competence division is often part of and sometimes even driving the empirical analysis. As a result, policy areas characterized by shared competences almost automatically fall into ‘medium’ categories with moderate and impractical recommendations. Empirical analyses related to the concept of actorness often do not ‘allow to separate EU and Member State action’.⁶⁵ Admittedly, also from a legal perspective the ‘in-between’ category of shared competences is often overlooked; the focus is often on exclusivity. Yet it is the broad category of shared powers where legal factual answers increasingly fall short in explaining what happens in practice. In these policy areas a combination of analysing formalities, case law and informal strategies would add to both new academic insights, and perhaps even to more effective diplomacy. It is especially in these policy areas that the current academic silos are problematic and a confrontation of legal and political perspectives would be helpful. The practical and well-documented example of EU climate negotiations in the next section points to the necessity of an integrative analytical framework.

A final bridge between legal and political studies on EU external relations may be found in the attention both disciplines pay to ‘institutions’ and ‘institutionalization’. The notion that ‘institutions matter’ is fundamental to the approach in both many political science and legal approaches. Indeed, this may very well be one of the ‘nodal points’ where law and politics are closely intertwined.⁶⁶ One clear example is formed by institutionalist explanations of the existence of external powers. The idea that the ‘modes and effects of external governance are shaped by internal EU modes of governance’⁶⁷ is echoed in more legalistic contributions, where – in a way and perhaps ironically – EU external relations law is largely about an intra-EU competence division.

3.1 Effects of shared competences in practice

We found that the ‘shared competences’ legal framework has an effect on power relations in international climate negotiations in at least three ways. First, as a general basis, the nature of (external) competences is fixed by the Treaties. This is already an important step. As argued above, for the actual analysis of external power relations, it makes quite a difference whether a competence is exclusive, shared or supportive. Our case study reveals that this is recognized by the actors. Thus, for instance, the European Commission is (generally) the actor to contact in the World Trade Organization as trade is an ‘exclusive’ EU competence,⁷¹ irrespective of the fact that the Member States are still present. In international institutions where the EU and Member States ‘share competences’, such as the UNFCCC, the mentioned ‘nuanced’ nature of shared competences is indeed acknowledged and more fine-tuning is necessary. As one of the diplomats put it: sharing competences does not implicate a ‘fifty–fifty’ relationship.⁷²

Second, it is not only the Treaty that legally defines the conduct of power relations in international organizations; the CJEU’s case law is also to be used as guidance as it may provide further explanation of the often quite general Treaty rules and principles. Above, we have referred to the link between internal and external EU competences: whenever the European Union has elaborated measures in a particular policy area internally, it is generally allowed to conduct external relations in that domain. In that way, one of the Member State foreign services seems to be right on their website by expressing the opinion that the EU external competence framework is more of a dynamic than a static process.⁷³ Again, it is clear that political actors become aware of the dynamic changes in the division of competences once they are confronted with them in practice.

Third, there is a more specific delegation process derived from the sharing of competences in the policy area of climate change. The EU and its Member States have invented specific types of ‘actors’ in the multilateral climate negotiations, so-called ‘lead negotiators’ and ‘issue leaders’. These negotiators and issue leaders are chosen among the EU and Member State representatives, independent of their institutional origin. This inventive arrangement is an indirect consequence of the ‘shared competences’ in the environmental field and is recognized by the political actors.

A key question in the context of the present contribution is to what extent shared competences enable or restrain EU and Member State actors in the specific case of UNFCCC negotiations. Our case study revealed that shared external competences enable the European Commission to keep EU Member States as part of the negotiating team as there would be legal consequences when they would negotiate separately from the EU. Furthermore, internal legislation enables the European Commission as an EU actor to increase its coordinating role. However, it has also become clear that shared external competences restrain the European Commission as it is unable to side-line the Member States – something it can more easily do in external trade negotiations. As a mirror-image of this situation, shared external competences enable the EU Member State actors (large and small) to play a significant role in climate change negotiations. This sometimes leads to deep disagreement between Member States.⁷⁴ Poland, for example, could threaten with a CO ₂ veto until the last moment of climate change negotiations.⁷⁵ Shared external competences also restrain Member State actors. In the UNFCCC setting, Member State actors were looking for the ‘margins’ of what was agreed upon collectively to define a more detailed Member State profile, but there is a general settlement that it is not appropriate to ‘colour outside the lines’ – hence, to stay within the limits set by the legal competences.⁷⁶

Occasionally – and obviously – Member States consider an EU competence to be a ‘legal straitjacket’ that ‘forces them to coordinate’; they suspect it to be merely used by the Commission to expand its powers.⁷⁷ However, it is only when issues are getting ‘really political’ that rules, procedures and other legal issues become less relevant than political considerations. Prior to this situation, legal rules are indeed the main driver of the division of powers between EU and Member State actors, and in that sense they do define the conduct of international negotiations. Thus, one may tend to conclude that legal competences are the starting point, but that they are put into perspective once issues become very political (which is often the case in international negotiations).

Indeed, climate change is often portrayed as a very political, conflict-driven policy area because of the Copenhagen failure (2009). In that sense it is interesting to note that the interviews sketch a quite friendly internal EU policy negotiating environment during the negotiation of a common EU and Member States’ position. Our finding supports the idea that this more friendly environment is enabled by the legal competence framework which already sets the stage and renders some debates obsolete. The European Commission could start an infringement procedure when it is overruled by Member States in representation at climate change negotiations. However, it may choose not to do so purely on political grounds. As one of the interviewees puts it: the issue of climate change is too treacherous to bring a case to the CJEU.⁷⁸ This example makes clear that the Commission is hesitant in confronting Member States on their diplomatic behaviour when the stakes are higher at the international scene and, moreover, the topic itself is considered as ‘high politics’ for the EU. This, in turn, is a clear example of political influence on the use of legal rules and principles (and the other way around).

3.2 Other explanatory causes and theories

Apart from the formal rules on shared competences, other, more informal, possible explanatory causes and effects are also identified, including external incentives. Most theories focus particularly on the balance of power between (large) Member States, ‘socialization’ of representatives from Member States, and voting power of Member States and EU representatives.⁷⁹ For example, EU socialization means that EU Member States’ representatives involved in deciding on and negotiating the EU position in international institutions first and foremost adapt a European orientation.⁸⁰ Social norms cannot be put aside, but legal–institutional norms and the procedure derived from the legal competence framework may very well accelerate these social norms.

As indicated by the existing literature, ‘preference heterogeneity’ – in the sense of (the absence of) aligning interests – and (large) Member State power are also considered primary causes of EU and Member State negotiation behaviour. However, environment and climate change are ‘typical EU policy’ fields, where of course preference heterogeneity exists, but where there is a general tendency towards cooperation. The Commission would therefore be less inclined to start legal conflicts in this policy field. Furthermore, large Member States, such as the United Kingdom, see the overall added value of EU cooperation and EU competence in multilateral climate change negotiations which might also help.⁸¹ The EU’s engagement with strategic partners seems to be driven by a preference for an ambitious international climate deal. In that case, it could also help to analyse the use of other common instruments, such as trade, as leverage for a climate deal.⁸² Furthermore, the academic, professional or national background of the negotiator itself could have an effect on the conduct of negotiations. In the run-up to the large UNFCCC COP climate change conference, we found that more environmentally oriented policy officers prepared the negotiations, sharing not only competences but also background and knowledge. Only in the final phase of the conference did political leaders set the stage, which could lead to more (political) conflict.⁸³ Lastly, the statute of the international organization (and the question of whether the EU itself is a member of the organization, or whether it has to rely on its Member States to present the Union’s position) could lead negotiators to work together towards a common EU stance.

4.1 Why should legal and political perspectives be combined in shared policy areas?

There are at least six reasons why legal and political perspectives could and should be combined in an analysis of EU external action and why this combination would be particularly helpful to better understand areas defined by shared competences. First, in a combined approach many (implicit or explicit) assumptions in both approaches and theories can be tested more extensively and possible myths can be checked. For example, it is often stated that if only the EU would ‘speak with one voice’ its performance in a given international organization would be significantly improved⁸⁴ while others state that the ‘legal division of labour is seldom strictly followed in practice’.⁸⁵

Second, by combining legal and political insights, the conduct of EU external relations can be evaluated from (formal) input and process to (formal/informal) outcome and (informal) impact, thereby contributing to the evaluation of EU diplomacy as well as of the effects of treaty modifications or new case law on EU external relations.⁸⁶

Third, as has been visible in the UNFCCC example, sometimes competences do not explain the behaviour of EU and Member State actors, mostly due to political reasons. An integrative analysis contributes to finding this ‘breaking point’.

Fourth, as has been made clear in political contributions in particular, legal competences are only part of the authority of actors. There are other important sources of authority, including expertise, or the link with other policy dossiers.⁸⁷

Fifth, information on the usage of strategies, their effectiveness, as well as the response of third actors cannot be obtained from official documents and formal issues alone. Instead, this information needs to be gathered from interviews or process-tracing, which is part of the tool box of political scientists.⁸⁸ As regards these strategies, probably the diversity prevailing among EU Member States is also the ‘most precious asset’ when acting externally.⁸⁹

Sixth, the way competences are used as an intervening variable in political analyses and as guiding many legal analyses is problematic in case of shared competences. The recent attempt by da Conceição-Heldt and Meunier, for example, categorizes all policy areas of shared competences as ‘medium internal cohesiveness’ and concurrently ‘medium external effectiveness’, which does not reveal the specificities per policy area. It is questionable whether the EU and its Member States are indeed in the same vein ‘internally cohesive’ as well as ‘externally effective’ in contradicting policies such as ‘European Neighbourhood Policy’ and multilateral environment negotiations. The limitation of this focus on ‘internal cohesiveness’ based on competences is also visible in the article by Panke, who found that there is very low internal cohesion of EU actors in the UN General Assembly (UNGA) ‘since there is no exclusive or shared competence for EU action in the UNGA’. Yet, it is ‘remarkable’ that the EU succeeds in developing a common negotiating position most of the time, that is for about 95 per cent of all resolutions.⁹⁰ This is symptomatic of a political perspective on competences, in which it is not acknowledged that the policy areas as discussed in the UNGA are indeed already defined by legal competences and a related division of labour. Similarly, legal analyses often merely look for guidance to the Treaties and the CJEU, without any thorough analysis of the practical consequences in EU external action or its effectiveness.

4.2 Methodological and substantive considerations

While there thus are many good reasons to develop an integrative analytical framework, at least three considerations need to be addressed. First, as we have seen, shared competences are a broad category encompassing at least four different types.⁹¹ For a step-by-step analysis of shared competences at international institutions, it is helpful to differentiate between these sub-categories. Action on the basis of the sub-categories of shared competences can be assessed in case studies where different empirical findings and settings are combined.

Second, the methodologies used for political and legal perspectives are complementary but also difficult to combine in practice. Political scientists would normally use empirical evidence, backed up by secondary literature, and document analysis,⁹² while legal scholars would have a tendency to focus on legal texts and support their analysis mainly by what others have found as well. Despite the potential that is offered by combining empirical and conceptual/analytical methods in this particular issue area, prioritizing the information sources will be a challenge.

Third, diplomacy has traditionally been perceived as the prerogative of states and their representatives.⁹³ However, exclusivity of diplomacy as a state domain is challenged on several fronts, including the variety of areas that go beyond the immediate military and political dimensions of traditional diplomacy (e.g environmental diplomacy), the extension of involved actors, even parliaments.⁹⁴ For some, the ability to act externally as a state-like unit is indispensable to the very existence of the EU, and we have seen that the European External Action Service (EEAS) was created as an attempt to do exactly that.

4.3  Current limitations

The combination of legal and political insights could help in assessing shared external competences in practice and in particular their enabling or restraining effect on EU and Member State actors in international institutions. The present authors do, however, recognize some important limitations. First, while legal approaches, despite their variety, often share a focus on interpretations of the Treaties, decisions and case law, political science approaches are even more diverse. In fact, part of political science is characterized by debates on which theories and concepts are more fit to explain reality. In the absence of a generalizable approach it is difficult to bring ‘political theory’ in general closer to the legal approach and it is needed to pinpoint specific, more institutionalist, theories or concepts such as actorness or effectiveness to allow for a sensible connection. Second, the question of competences is ‘fundamentally also one of national constitutional norms’.⁹⁵ Therefore, some Member State actors or entities might be more oriented on the division of competences than others. For example, federal states such as Germany have experience with a clear-cut division of competences in their own constitution, while the United Kingdom does not have a single constitutional document. This can be pre-empted by taking into consideration ‘other explanatory variables’ in the analysis framework. Third, EU negotiations at, for instance, the United Nations tend to be multi-issue in scope, either because multiple issues are formally under discussion at the same time and thus subject to explicit trade-offs or because actors’ preferences with regard to upcoming issues can be leveraged against present concessions.⁹⁶ Such ‘multi-issue negotiation’ complicates the assessment of competences in practice and combining approaches as both approaches would not analyse the whole chain of negotiations in international organizations such as the UN. Nevertheless, we would argue, this would be much easier recognized when political and legal insights are combined, rather than taking a single academic perspective.

Additional methodological challenges with regard to a politico-legal analysis of shared competences in international negotiations relate to the fact that the work of the preferred study objects (EU and Member State diplomats) is surrounded by ‘secrecy’ and anonymity.⁹⁷ It is necessary to hear different sides and also keep the interviews confidential. By combining multiple interview sources (diplomatic/academic) and studies (expert sources/case law), the analysis allows for a triangulation of findings.

As already observed by Macaj and Nicolaidis, ‘to assess whether a desirable outcome in the world has anything to do with some action taken by the EU or its member states, let alone with the fact of unity itself, is at best an exercise in probability. Correlation does not imply causation and even careful process tracing gives us at best a sense of likelihood of impact.’⁹⁸ The preliminary findings can thus best be characterized as ‘plausibility probes’ only, providing interesting avenues for future research. These plausibility probes would need further testing in other cases to become more robust.⁹⁹ They make conditions under which the EU can turn into an effective external actor more clear, even in contexts in which its (formal) actor capacities are very limited.¹⁰⁰ Yet, the in-depth interviews and ‘plausibility probes’ might be a very relevant addition to the literature as most studies focus only on voting outcomes and/or representation statements, which merely reflect the outcome of a ‘longer chain of decision-making and cannot capture the essence of the process before this final decision’.¹⁰¹ Voting outcomes ‘do not provide insight into the extent that different actors actually managed to influence the content of resolutions’, but only give an indication of which states are not satisfied with the negotiation outcome.¹⁰² Case studies are better equipped to answer ‘how and why questions’, as Yin puts it.¹⁰³ However, as Blatter and Haverland contemplate, case-study research has also been an excuse for ‘methodologically unreflective research’ in recent academic history.¹⁰⁴ A reflection on the commonalities and differences in the cases and the difficulties in practice should thus be included.