General Principles and Fundamental Rights Review in the Common Foreign and Security Policy after KS and KD v Council et al.: A Missed Opportunity for the Rule of Law

Table of Contents: 1. Introduction – 2. Background to the case: KS and KD in a legal blackhole – 3. CJEU jurisdiction and the curious argument from the principle of conferral – 3.1 Conferral as a principle of integration – 3.2 Fundamental rights review as constitutionalisation, not integration – 3.3 Shift from conferral to consent in the Court’s reasoning? – 3.4 Implications for the interpretation of Articles 24 TEU and 275 TFEU– 4. A Principled approach to jurisdiction in line with EU constitutional and general principles – 5. Specific interpretive approaches to the exclusion of jurisdiction in Articles 24(1) TEU and 275 TFEU – 5.1 Casuistic expansion of jurisdiction before KS and KD – 5.2 Jurisdiction as a rule or an exception after KS and KD? – 5.3 Missed opportunities for an incremental interpretation of the Treaty provisions – 6. The road not taken: missed opportunities for general principles, the rule of law and constitutional resilience – 6.1 Informing interpretation and furthering coherence – 6.2 Filling gaps – 6.3 Developing constitutional hierarchy in the EU – 6.4 Implications for the rule of law and constitutional resilience.

Abstract: The article critically reviews the state of play of judicial review in the CFSP after the Grand Chamber judgment of 10 September 2024 in KS and KD. The decision creates a potential pathway to closing some gaps in fundamental rights protection in the CFSP and, thus, advances judicial protection. However, the CJEU also missed an opportunity to constitutionalise the EU legal order by articulating a principled approach to judicial review in the CFSP based on EU core values. General principles of EU law could have assisted the Court in developing such a principled constitutional approach because of their specific characteristics and functions: as gap-fillers and as enhancing coherence and legitimacy when developing the EU legal order. 

Keywords: judicial review in the CFSP – general principles of EU law – rule of law – constitutional resilience – unwritten sources of law – principle of conferral – coherence. 

1.   Introduction

The Grand Chamber judgment in KS and KD of the Court of Justice of the European Union (CJEU, Court)[1] provided a pathway to closing a gap in judicial protection in the Common Foreign and Security Policy (CFSP), even though this has, till date, not helped the applicants in casu.[2] This article reflects on the CJEU’s approach in developing judicial protection in the CFSP and strengthening the rule of law in the EU. 

While developing the law and (most likely) expanding judicial review in the CFSP, the absence of an explicit reference to general principles of (EU) law in the reasoning of the Court is noteworthy. This is even more so, since KS and KD based their appeal on general principles, arguing that the exclusion of the jurisdiction of the CJEU should be interpreted 

‘in the light of the core rules of EU primary law and the general principles of EU law, in particular the principle of the rule of law and the right to an effective remedy, which apply to all areas of EU law, including the CFSP’.[3]

Similarly, also the Advocate General Ćapeta’s proposed solution invoked general principles when she criticised the General Court’s judgment under appeal for 

‘neglecting entirely the general principles that underpin those cases and are applicable in any case that requires an interpretation of the limits of the EU Courts’ jurisdiction in the CFSP’.[4]

Substantively, general principles – the rule of law, fundamental rights and effective judicial protection – inevitable loom large in the case. However, they remain only its backcloth. They underpin the Court’s outcome and inform implicitly its reasoning, but general principles as a separate, independent source of EU law do not form the basis of its reasoning. It might be argued that because of the codification of the rule of law, fundamental rights and effective judicial protection in the Treaties and the EU Charter of Fundamental Rights (EUCFR, Charter) as constitutional principles, it would not be necessary to engage with the unwritten general principles: where there are written norms, one would not need to invoke unwritten ones; arguably, doing so, may even pose risks for the rule of law.

In contrast, this article will reflect on the actual and potential role and, thus, added value, of general principles in determining the extent of fundamental rights review in the CFSP after KS and KD v Council. It will, thus, not only critique the reasoning,[5] or the outcome as going against the explicit wording of the Treaties.[6] Beyond that it will provide a way forward to resolving the apparent conflict between judicial protection and the explicit exclusion of CJEU jurisdiction, which is rooted methodologically in general principles as a source of EU law which applies in parallel with Treaty text. It will argue that an opportunity was not seized to articulate and develop further a principled constitutional approach, based on EU core values and their hierarchy in the EU’s constitutional framework. Instead, the Court potentially opened a pandora’s box by reading a latent political questions doctrine into EU law, which is not only problematic in modern constitutional states, but leaves residual concerns about whether the judgment is sufficient to allow for EU accession to the ECHR.

This article will first briefly outline the background of the case of KS and KD, including its procedural history and context (2. below). It will then discuss and critique the interpretation and approach the CJEU has taken. It will first argue how a misapplication of the principle of conferral limits the Court’s hands in adopting a more constitutionally principled approach to justifying jurisdiction in the CFSP against the wording of the Treaties (3.). It will then sketch an alternative, more principled approach, in line with the Advocate General. (4.) It will then contour how the Court might have continued its incremental approach without having had to rely on a type of political questions doctrine (5.). Finally, the article will reflect on how the judgment is a missed opportunity in several dimensions. It will discuss how reasoning from the general principles of EU law could have contributed to the coherence and legitimacy of the foundations for judicial review in the CFSP, and how this, in turn, could contribute to greater resilience of the rule of law in the EU (6.).

2.   Background to the Case: KS and KD in a Legal Blackhole

The applicants, KS and KD, are family members of persons who disappeared or were killed in the aftermath of the NATO intervention in Kosovo. Kosovo was at the time under the administration of the United Nations Interim Administration Mission in Kosovo (‘UNMIK’) which exercised state-like authority. UNMIK’s responsibilities were later in 2008 transferred to EULEX Kosovo, a large-scale civilian mission to build institutional capacity in justice and the rule of law in Kosovo. EULEX was established under the EU Common Security and Defence Policy (CSDP) which forms part of the CFSP. EULEX exercised extensive powers by either acting directly or supporting institutions of Kosovo. Since 2014 the mission has been progressively reduced with the aim or winding it up. Its own executive functions in Kosovo have ceased.

In casu, KS and KD are claiming damages under Article 340 of the Treaty on the Functioning of the European Union (TFEU) for violations of their human rights under the European Convention on Human Rights (ECHR) and the EU Charter on Fundamental Rights (EUCFR). Their claim is based on the procedural duties to investigate, arising from the right to life and the prohibition of torture (Articles 2 and 3 ECHR, Articles 2, 4 EUCFR) and the right to a remedy (Articles 6, 13 ECHR, Article 47 EUCFR), because of the failure to take remedial action and misuse or abuse of executive power by the Council, Commission and European External Action Service (EEAS). 

The applicants had previously lodged complaints before the available advisory review mechanisms: initially before the UNMIK Human Rights Advisory Panel and later before the Human Rights Review Panel (HRRP), established under EULEX Kosovo. The HRRP found violations, inter alia, of Articles 2 and 3 ECHR and made recommendations to the EULEX Head of Mission. But the Panel’s recommendations were not fully implemented. It is suggested that this was, in part, due to a scaling down of the mission and inadequate resourcing. 

Before bringing their damages action in the General Court,[7] the applicants brought a series of unsuccessful challenges in the EU and national courts: a direct challenge for omission to act in the EU General Court;[8] and several unsuccessful actions in the domestic courts of the UK. The High Court and Court of Appeal held that UK courts lacked jurisdiction over claims about violations of Articles 2 and 3 ECHR in Kosovo because they resulted from extraterritorial acts, and that the acts would also not be attributable to the UK.[9] In an action for damages against the European Union[10] the UK High Court ruled that it lacked jurisdiction due to an ‘insurmountable hurdle’ of a ‘technical’ nature: because of the UK’s dualist approach to international law the CFSP provisions were not applicable directly in domestic law because they were not incorporated by the European Communities Act 1972.[11] It also considered the CJEU to have exclusive jurisdiction over damages actions according to Articles 268, 340(1) TFEU, that the Foto-Frost[12] ruling applied and prevented it from pronouncing on the legality of acts within the CFSP. Moreover, it refused to refer the question whether a national court was competent to provide a remedy under Article 19(1) of the Treaty on European Union (TEU).[13] This shines a light on the de-facto incompleteness of the system of legal remedies against an act in the CFSP which may violate fundamental rights, contrary to the CJEU’s constant jurisprudence since Les Verts and Opinion 2/13.[14] It required the applicants to pursue a claim for damages in the EU courts as a last resort.

In the present proceedings in KS and KD, the General Court had dismissed such an action for damages at first instance because of a manifest lack of jurisdiction: Article 275(1) of the Treaty on the Functioning of the European Union(TFEU), as a rule, precludes its jurisdiction for measures in the CFSP, and none of the two exceptions of Article 275(2) TFEU applied on the facts. The action (1) did not concern the monitoring of compliance with competences according to Article 40 TEU; and (2) was not about reviewing the legality of individual restrictive measures, e.g. sanctions listings. This is because restrictive measures have been narrowly defined as decisions adopted under the CFSP under Articles 215 TFEU, 29 TEU (Title V chapter 2).

In the appeal proceedings, Advocate General Ćapeta delivered a principled Opinion affirming the jurisdiction of the CJEU for violations of fundamental rights, interpreting the specific rules in the CFSP in the light of overarching constitutional principles of the EU: 

‘In a Union based on the rule of law, it could not have been the intention of the authors of the Treaties to allow for breaches of fundamental rights in the CFSP. As the breach of a fundamental right cannot be a policy choice, the EU Courts must be able to control whether that limit was crossed’.[15]

The CJEU’s Grand Chamber followed the Advocate General insofar as it also upheld the possibility of its jurisdiction in the case. But it deviated from her Opinion in rejecting arguments derived directly from constitutional principles (rule of law, fundamental rights) as incapable of conferring jurisdiction in and of themselves.[16] According to the CJEU, assuming jurisdiction based on constitutional principle despite the explicit exclusion by the Treaties would run counter the principles of conferral and institutional balance because the Union, through the Court, would act outside the competences conferred on it by the Member States.[17] This reasoning means the CJEU does not automatically have jurisdiction over a measure in the CFSP that engages fundamental rights. In other words, a right does not necessarily entail a remedy in the context of the CFSP – in contrast to the evolution of EU law in other areas.[18] In doing so, the Court distinguishes the violation of fundamental rights by a CFSP measure from the interpretations of Article 275 TFEU in the more specific context of restrictive measures. 

Nevertheless, the constitutional values of the rule of law and fundamental rights, and, thus, the general principles of EU law, are forming the background of the CJEU’s approach to justify its jurisdiction in the case. The language of the rule of law and fundamental rights looms large in the judgment,[19] including their applicability in the CFSP. For example:

‘the inclusion of the CFSP in the EU constitutional framework means that the basic principles of the EU legal order also apply in the context of that policy. These include, in particular, respect for the rule of law and fundamental rights, values expressed in Article 2 TEU and given concrete expression to in Article 19 TEU, which require that both EU and Member State authorities be subject to judicial review’.[20]

Nonetheless, the Court resorts to a rather more roundabout solution of a corrective interpretation of Article 275 TFEU. In doing so, the CJEU takes pains to argue that the exclusion of jurisdiction can be justified under the ECHR.[21] In essence, the CJEU requires to still consider the explicit exceptions from the exclusion of jurisdiction in Article 275 TFEU first. Only if none of the explicit Treaty exceptions are applicable, the exclusion of CJEU jurisdiction in the CFSP may be read down on condition that the ‘issue [is] not directly related to … political or strategic choices’.[22] In other words, the Court stays, at least prima facie, closely to the text of the Treaties, but then inserts a new, and arguably problematic, political question doctrine into Articles 24(1) TEU, 275 TFEU, to allow for balancing of the wholesale exclusion of the jurisdiction in the text of the Treaties with the right to a remedy in the individual case. But this assumes structurally that as a rule the Court has jurisdiction, if a case is not about political or strategic choices. However, this rule-exception relationship is not articulated directly. 

‘115. … in examining the jurisdiction of the Court of Justice of the European Union to hear and determine an action concerning acts or omissions falling within the scope of the CFSP, it is necessary to ascertain, first, whether the situation at issue falls within one of the situations provided for in the last sentence of the second subparagraph of Article 24(1) TEU and the second paragraph of Article 275 TFEU, in which that jurisdiction is expressly allowed.

116. If that is not the case, it is necessary, second, to assess whether – as is apparent, in essence, from the case-law […] – the jurisdiction of the Court of Justice of the European Union may be based on the fact that the acts and omissions at issue are not directly related to the political or strategic choices made by the institutions, bodies, offices and agencies of the Union in the context of the CFSP, and in particular the CSDP.

117. Thus, if the acts and omissions at issue are not directly related to those political or strategic choices, the Court of Justice of the European Union has jurisdiction to assess the legality of those acts or omissions or to interpret them. By contrast, if those acts or omissions are directly related to those political or strategic choices, that institution must declare that it lacks jurisdiction’.[23]

The case was referred back to the General Court which was expected to rule on whether ‘political and strategic choices’ were affected, and thus whether it had jurisdiction over the violations raised by KS and KD, and whether the additional conditions for damages were met. It might also have been expected that KS and KS’s claim would at least in part succeed in the General Court. In a surprising move, however, the General Court dismissed the action as ‘manifestly inadmissible’ in September 2025 on the grounds that the violations could not be attributed to the defendants (Council, Commission and EEAS) because they fell, as day-to-day management issues, into the exclusive responsibility of the EULEX mission.[24] It is to be noted that in the domestic context in the UK the EULEX mission was initially a defendant but the claim against EULEX was dropped in the High Court,[25] demonstrating the complexity of judicial protection beyond the question of CJEU jurisdiction. Although the High Court was sympathetic to having jurisdiction ‘as a matter of EU law under Article 19(1) TEU in relation to a CFSP matter, it considered that such jurisdiction was precluded ‘as a matter of domestic law’ because English courts were precluded from considering the unincorporated CFSP provisions which were excluded ‘from the definition of “the Treaties” in section 1(2) of the European Communities Act 1972’.[26] The High Court did not consider a review of the CFSP mission against domestic fundamental rights of the United Kingdom (i.e. the ECHR through the Human Rights Act – which could have provided an impulse for the EU). The KS and KD saga thus also demonstrates that national courts may not be willing or able step in. Thus a legal blackhole in the context of the CFSP arises which contradicts the mantra of a complete system of legal remedies in the EU.[27]

The article will now turn to demonstrating how a too restrictive reading of the principle of conferral is at the heart of precluding various options to interpret the Treaties in conformity with the rule of law, before outlining various options for interpretation.[28]

3.   CJEU Jurisdiction and the Curious Argument from the Principle of Conferral

While one might have thought that KS and KD would be granted access to justice in the General Court, the General Court’s turn suggests that it wanted to avoid ruling on the issue. The silver lining is that, at least for now, no attempts have been made to flesh out what ‘political and strategic choices’ mean, a concept best abandoned. In the following, it will be examined how the CJEU could have approached, in a principled manner, the question whether CFSP measures may be subject to fundamental rights review, notwithstanding the explicit exclusion of such jurisdiction by the Treaties. At the same time, it must be acknowledged that the Court is in a difficult position when seeking to assume jurisdiction in the face of the express wording of the Treaties. Such a stance might trigger criticism of contra legem interpretation of the Treaties and ‘judicial activism’. Nevertheless, judicial activism ought not to be confused with constitutional adjudication.[29]

The Court’s reluctance to weigh directly the jurisdictional exclusion in Article 24(1) TEU and Article 275(1) TFEU against the values of Article 2 TEU rests in part on the structural general principles of conferral and institutional balance. This is despite acknowledging that the constitutional principles of Article 2 TEU apply in the field of the CFSP. [30] As the Court reiterated, 

‘in accordance with Article 5(1) and (2) TEU, “the limits of Union competences are governed by the principle of conferral”, that principle meaning that “the Union shall act only within the limits of the competences conferred upon it by the Member States in the Treaties to attain the objectives set out therein…”. Competences not conferred upon the Union in the Treaties remain with the Member States’.[31]

This line of reasoning echoes the position advanced by the Council, which invoked the general principle of good administration to resist a more expansive reading of the Court’s jurisdiction.[32]

However, it may be questioned whether the principle of conferral is appropriately deployed to justify the restriction of judicial review in a manner that may constrain the right to an effective remedy and, ultimately, the rule of law in EU foreign policy. Even if it is assumed for the sake of argument that conferral applies to jurisdiction of the Court, it is not evident that it should prevail over competing constitutional principles of the rule of law and fundamental rights (the right to a remedy). As argued below,[33] a balancing can occur through the interpretation of the Treaty text, including the provisions excluding the Court’s jurisdiction. Where rights exist, remedies must follow, a principle inherent in the Treaties’ constitutional architecture and central to the Court’s case law on the autonomy and completeness of the system of remedies in the EU.[34] It is argued that relying on the principle of conferral confuses the logic of integration and of constitutionalisation in turn, and may reflect political rather than legal concerns.

3.1.  Conferral as a principle of integration

The principle of conferral in Article 5 TEU relates to the allocation of substantive competences to attain the Union’s objectives. The exclusion of jurisdiction in the CFSP reflects Member States’ concerns at the time of creating intergovernmental cooperation in in foreign policy, dating back to the Maastricht Treaty in 1992, that the Court might replicate in foreign policy the substantive integrationist dynamic that had characterised its case law on the internal market. That concern explains the drafters’ attempt to distinguish the paradigm of intergovernmental cooperation in the second pillar from the integrationist logic of the first. Although the pillar structure was formally abolished by the Lisbon Treaty, the jurisdictional limitations were retained, despite the substantive evolution of the CFSP, producing the well-known tension between the distinctiveness of the CFSP and the broader constitutional unity of EU law.[35] As Koutrakos has argued, the CFSP is an ‘unfinished’ policy in ‘transition’ which reflects two conflicting normative impulses: distinctiveness and integration. He suggested—writing before the KS and KD litigation—that while deeper integration of the CFSP may be desirable, it should not be achieved through a teleological re-reading of Article 275 TFEU, which would go beyond the judicial function and require Treaty reform by the Member States.[36] However, the gap in judicial protection created by the evolution of the CFSP, and exposed by the KS and KD litigation, demonstrates not only the need for that gap to be filled, but also the inadequacy of a framing solely through the binary integration versus distinctiveness. That binary must be supplemented by a third normative lens — constitutionalism — which intersects with both – but has a conceptually distinct rationale from either. 

3.2.  Fundamental rights review as constitutionalisation, not integration

That binary framing risks reductionism. It treats the extension of judicial review as inseparable from the substantive integration of CFSP decision-making into the ordinary Union method. However, strengthening judicial review does not necessarily advance integration but may instead limit the exercise of EU power.[37] As de Baere pointed out, equating jurisdiction with integration as inseparable aspects[38] of the ‘ordinary Union method’[39] collapses analytically distinct dynamics of integration on the one hand and constitutionalisation and accountability on the other hand.

Constitutionalisation in this sense performs a self-limiting function, rooted in the idea that the Union is founded on the rule of law and may not exercise its conferred powers in a manner that violates fundamental rights. That understanding does not require the Union to possess a substantive harmonising competence. Although the rule of law and fundamental rights are both now written constitutional norms of the EU legal order, they have been recognised and continue to exist, as parallel general principles common to the constitutional traditions of the Member States from which they originate: all public authority is limited by fundamental rights.

The very genesis of fundamental rights in the EU demonstrates this. Without a general or harmonising competence over fundamental rights, the idea of EU fundamental rights originally has been built on the power of the EU to limit itself – for example, through general principles.[40] Fundamental rights thus are inherent in the conferred substantive competence to act, or indeed in the practical capacity of the EU to act in the first place. Such limits may derive either from a general principle rooted in the constitutional traditions common to the Member States[41] or be considered inherent in the powers or the very nature of an international organisation.[42] If considered in this way, the principle of conferral loses its force as an argument to limit the application, and by extension, enforcement of fundamental rights in the CFSP. Conferral belongs to the realm of integration, whereas the constitutional limits apply inherently to any EU action, including the CFSP, and jurisdiction of the Court makes these limits effective.

3.3.  Shift from conferral to consent in the Court’s reasoning?

If the Court’s reasoning is examined closely, its reliance on conferral also appears to function as a proxy for different concerns: firstly, a legal concern about the consent (and ultimately, sovereignty) of the Member States linked to judicial review in the CFSP; and secondly, a legitimacy concern that may arise from anticipated perceptions that the Court would go too far by allegedly applying the Treaties contra legem – which may trigger push-back against the Court. From an international law perspective, the jurisdiction of an international court is indeed grounded in state consent. The principle of conferral in the vertical dimension of integration vis-à-vis the Member States reflects this dimension.

However, if one takes seriously the Court’s case law from van Gend to Opinion 2/13[43] on the characteristics of the EU legal order which is not merely an international organisation but a constitutional legal order with (a certain degree of) autonomy and constitutional authority, such a conception of consent must be modified, at least in the relation to individuals: a legal order in which individuals are subjects rather than mere beneficiaries of international agreements[44] does require an (allegedly) complete system of legal remedies, removed from such a conception of consent. Therefore, the argument from consent/conferral carries less force where that context is not one of integration but one of limitation and accountability of the EU’s exercise of power. 

The EU’s legal personality, and the presence of inherent limits derived from general principles of EU and international law—including proportionality, fundamental rights, and the rule of law—support the view that the Union possesses a corresponding inherent power of self-limitation. This power must be judicially enforceable if it is to be meaningful. Moreover, the remedy cannot be hypothetical or deflected to other legal entities, such as the Member States’ legal orders and courts. The playing out of the KS and KD saga in the Tomanovic cases in UK domestic courts demonstrate the problems of deflection and deference, and, thus, loopholes for accountability, particularly in the context of foreign policy.[45]

3.4.  Implications for the interpretation of Articles 24 TEU and 275 TFEU

Accordingly, an argument against judicial review in the CFSP based on conferral does not preclude an interpretative approach consistent with the rule of law. As argued in the previous section, fundamental rights review in the CFSP does not concern the integration paradigm behind the principle of conferral. To invoke the principle of conferral in the context of jurisdiction is to commit a category mistake, conflating the allocation of competence with the exercise of judicial authority. Therefore, it is also unwarranted to balance the exclusion of jurisdiction clauses in the Treaties against the rule of law where a direct conflict with fundamental rights arises; the question whether the same applies to measures that would integrate the CFSP need not be determined for present purposes. 

By creating the additional qualification that jurisdiction is excluded only if ‘political and strategic issues’ are concerned, the Court opens the possibility to balance rule of law and the exclusion of jurisdiction. This enables it to retain control over the scope of its jurisdiction in future by adopting a case-by-case approach, allowing it to assume jurisdiction in a wide range, possibly the majority, of cases notwithstanding the Treaty exclusion. Whether such an unprincipled approach is truly required in the context of deeper foreign policy integration may be debatable,[46] but it is unwarranted outside that setting.

The exclusion of jurisdiction in Articles 24(1) TEU and 275(1) TFEU may therefore be read down so as not to exclude judicial review where fundamental rights, as constitutional and general principles of Union law, are at stake, allowing EU constitutional and general principles to guide interpretation or fill any gap. This must be especially so in a foreign policy context as an area where neither Member State responsibility nor alternative remedies are sufficiently clearly established to protect individuals. The KS and KD – Tomanovic saga of cases demonstrates in fact the incompleteness of the system of remedies in the EU. Accountability of the EU, including in security and foreign policy, cannot be reduced to a by-product or collateral damage, as the case may be, of integration.[47]The Court would remain within, not beyond, its constitutional mandate in ensuring that the CFSP does not create rule-of-law-free zones.

4.   A Principled Approach to Jurisdiction in Line with EU Constitutional and General Principles

If the argument based on Treaty text and the principle of conferral does not categorically preclude jurisdiction in the context of fundamental rights because the principle of conferral is inapplicable here, there are two options: a principled approach or a more specific interpretive approach to the text of Articles 24(1) TEU and 275 TFEU that departs from their explicit wording.

The constitutionally more appropriate and more logical consequence for a case like KS and KD would have been to strengthen the principle of CJEU jurisdiction as a rule where EU action may lead to fundamental rights violations. This would not exclude balancing in the context of fundamental rights, but this would more appropriately happen in the merit phase of a claim, i.e. not as part of an assessment whether a claim is justiciable in the first place. The Opinion of Advocate General Ćapeta is exemplary both in its detailed technical analysis of a more principled approach and for taking into view the wider context: the significance of the Court’s judgment in KS and KD for the rule of law in the light of its challenges from multiple directions.[48]

The principled approach as exemplified by Advocate General Ćapeta may be summarised in brief: first, the rule of law and fundamental rights and effective judicial protection are basic constitutional principles of the EU legal order in Article 2 TEU which apply to all EU activities,[49] and even when acting outside of the EU legal order, by subject matter and geographically.[50] Second, the principles apply to the CFSP which has been included in the EU constitutional framework since the Treaty of Lisbon.[51] Third, they carry a special weight as an ‘integral part of the very identity of the European Union as a common legal order’, as the Court had told Hungary and Poland in response to their challenge to the competence of the EU to enforce the rule of law against them.[52]Fourth, judicial review and an individual right to effective judicial protection are a core element of the rule of law and fundamental rights.[53] Fifth, the principles, including effective judicial protection, apply to the EU and the Member States.[54] Sixth, for the EU this means that the CJEU must have jurisdiction as part of its mandate under Article 19(1) TEU.[55]

The CJEU – naturally – agreed with all these points,[56] but as discussed, it felt constrained by the wording of Articles 24(1) TEU and 275 TFEU, in the light of its understanding of the principle of conferral and an attempt of textual fidelity.[57] In the words of Advocate General Ćapeta:

‘These basic principles of EU constitutional law, namely the rule of law, effective judicial protection and protection of human rights – which justify the Court’s judgments in which it found that the limitation of its jurisdiction in Article 24(1) TEU and Article 275 TFEU is an exception, not the rule, and has to be interpreted narrowly – were ignored by the General Court in the order under appeal. The General Court distinguished the Court of Justice’s judgments in Elitaliana, H and Bank Refah from the present case on the basis of narrow and formalistic reasoning. It essentially held that those judgments were not comparable to the situation in the present case simply because they arose in a different factual context, thereby neglecting entirely the general principles that underpin those cases and are applicable in any case that requires an interpretation of the limits of the EU Courts’ jurisdiction in the CFSP’.[58]

A principled approach to ‘essentially “a human rights damages claim” arising under EU law in relation to a CFSP measure’,[59]in line with the Advocate General, would have been preferable. It is largely for this reason that the judgment of the Grand Chamber constitutes a missed opportunity to strengthen the rule of law and the EU’s constitutional resilience.[60] The Commission and almost all (eight out of nine) intervening Member States supported such a principled approach.[61]

However, in its absence, several more incremental, text-based interpretive avenues under Articles 24(1) TEU and 275 TFEU could still have moved in the same direction, while avoiding the opening of a Pandora’s box in the form of a type of political-question doctrine.

5.   Specific Interpretive Approaches to the Exclusion of Jurisdiction in Articles 24(1) TEU and 275 TFEU

Since Opinion 2/13[62] the Court of Justice has progressively expanded the scope of judicial protection in the CFSP, gradually reducing the significance of the jurisdictional exclusion contained in Articles 24(1) TEU and 275(1) TFEU. Although the Treaties still set the CFSP apart through ‘specific rules and procedures’, the case law increasingly suggests that the traditional rule–exception paradigm is being reversed. Against this background, KS and KD represent both a continuation or even step-change of this trajectory, although it also raises its own questions and problems.

5.1.  Case-by-case expansion of jurisdiction before KS and KD

The original exclusion of the CFSP from judicial review dates back to the Maastricht Treaty second-pillar structure and survived the Amsterdam and Nice revisions.[63] With the Treaty of Lisbon, the pillar system was abolished, yet the CFSP remained subject to specific rules. Crucially, Article 275(2) TFEU introduced two specific exceptions: judicial review concerning the boundaries between the CFSP and integrated competences, and judicial review of restrictive measures. The latter exception responded to the growing need for fundamental rights protection in terrorism sanctions cases, as exemplified by the Kadi case[64] in the EU and comparable litigation in the Member States.[65]

Even within this constrained framework, the exclusion of jurisdiction in Article 275(1) TFEU was increasingly narrowed through three distinct lines of case law.

First, the Court widened the explicit exceptions in Article 275(2) TFEU in the context of restrictive measures which refers only to annulment actions brought by individuals under Article 263(4) TFEU.[66] However, the Court expanded this to additional procedural routes:

a) Preliminary rulings on legality (Rosneft, 2017[67]): the CJEU held that it had jurisdiction to assess the legality of restrictive measures via Article 267 TFEU, citing the complete system of legal remedies in the EU and the Foto-Frost[68] doctrine that prevents national courts from declaring an EU act as invalid.[69]

b) Damages actions (Bank Refah, 2020[70]): the Court extended jurisdiction to CFSP damages actions arising from restrictive measures, emphasising that limitations on CFSP review must be interpreted restrictively.

c) Preliminary rulings on interpretation (Neves77 Solutions, 2024[71]): the Court confirmed that even general restrictive measures—without individual concern—could be interpreted via Article 267 TFEU.

A second strand of cases recognised jurisdiction where claims arose coincidentally in the context of CFSP missions but did not concern their political or strategic character.[72] In Elitaliana, H, and SatCen,[73] the disputes involved procurement, employment, or operational decisions. While CFSP provided the factual background, the legal issues were not inherently CFSP-specific. The Court, therefore, accepted jurisdiction, avoiding gaps in judicial protection.

A third line of cases ensured institutional balance in CFSP treaty-making. The Court affirmed jurisdiction to enforce compliance with EU constitutional procedures, protecting the competences of the European Parliament under Article 218(6) TFEU,[74] even when the underlying agreement concerned the CFSP. Despite these expansions, significant gaps persisted. Before KS and KD, there was no general access to:

a) preliminary rulings (Article 267 TFEU) outside the restrictive-measures context, creating a risk of inconsistent national judicial review and tension with the Foto-Frost principle;

b) CFSP-related damages actions unrelated to restrictive measures where the damage was coincidental to the CFSP context (Articles 268, 340 TFEU);

c) infringement proceedings in the CFSP (Articles 258-260 TFEU).

The case of KS and KD falls in the gap of damages actions not involving restrictive measures. But the case closely resembles the damages action in Bank Refah[75] in the context of restrictive measures. It might also be considered to have arisen merely in the context of a CFSP mission, like in the second line of cases.[76] So the Court could have grounded jurisdiction in expanding existing categories in the case-law further, or it could have adopted the principled approach suggested by the Advocate General. Instead, the Grand Chamber articulated a fourth scenario, framing the exclusion of jurisdiction through a new interpretive criterion of ‘political and strategic issues’ that further unsettles the rule–exception paradigm of jurisdiction in the CFSP.

5.2.  Jurisdiction as a rule or an exception after KS and KD?

At first glance, KS and KD appears to establish jurisdiction as the rule, with a newly formulated exception for ‘political and strategic issues’. However, this first impression must be qualified in two ways. The scope of this exception remains unclear, and the Court continues to frame its analysis in a roundabout way through the lens of Article 275(2) TFEU, that is as an exception from the textual exclusion of jurisdiction, rather than the through principle of jurisdiction. Structurally, therefore, jurisdiction in the CFSP still presents as the exception rather than the rule.[77] It is, therefore, uncertain whether the judgment fundamentally reorients the rule–exception paradigm for jurisdiction in the CFSP.

Despite acknowledging that interpretation of Articles 24(1) TEU and 275 TFEU must take into account not only the wording, but also context, objectives and purpose of the Treaties[78] and that the Union’s constitutional values, including Articles 2 and 19 TEU also apply in the CFSP[79], the Court prioritises a literal reading of Article 275 TFEU. Fundamental rights, particularly Article 47 EUCFR, are acknowledged but treated as incapable of conferring jurisdiction ‘where the Treaties exclude it’.[80] This approach subordinates the guarantee of judicial review of Article 19 TEU to the textual carve-outs in Article 275(2) TFEU, lowering the threshold for justifying an exclusion of review.

Thus, the CJEU created a pathway for an appropriate outcome in the individual case through a flexible political question doctrine, following the argument of the Council and EEAS. Both had called for a ‘suitable criterion’ to delimit jurisdiction that clearly distinguishes ‘discretionary policy decisions’ from ‘administrative acts aimed at the implementation of concrete actions.’[81]These were reflected, but also put in perspective, in the more principled approach of Advocate General’s Opinion.[82] It may be noted that such a test already exists, albeit not at the level of jurisdiction. The question whether an interference with a fundamental right is justified is a suitable test to distinguish a breach of fundamental rights from a permitted discretionary policy decision.

The likely (it is hoped), but not certain, practical effect of the Court’s approach may be that many fundamental rights claims will fall outside the ‘political and strategic issues’, and that jurisdiction will often be affirmed. The Court thus attempts to ‘have its cake and eat it’: it preserves the appearance of adherence to the Treaty text while mitigating denial of justice. However, the price is a novel, alien political questions doctrine that poses a wider risk for judicial review in the EU. In particular, the Court did not reject the possibility that the breach of fundamental rights may be a policy choice that could be immune from judicial review. The principled approach of Advocate General Ćapeta, in contrast, rules that out, stating that 

‘in constitutional democracies, policy choices are not unlimited. In a Union based on the rule of law, it could not have been the intention of the authors of the Treaties to allow for breaches of fundamental rights in the CFSP. As the breach of a fundamental right cannot be a policy choice, the EU Courts must be able to control whether that limit was crossed. Only in this way can they fulfil their mission that in the interpretation and application of the Treaties the law is observed’.[83]

A systematic constitutional interpretation would have treated the exclusion of jurisdiction as a strictly limited derogation which needs to be justified against the overarching constitutional principles of the Union. The Advocate General’s Opinion in KS and KDsketched out such a principled approach. Section 6 will discuss in more detail how general principles of EU law could strengthen such principled interpretation. The Court declined to adopt such a broader principled constitutional interpretation choosing instead to frame the analysis through the wording of Article 275(2) TFEU. Nonetheless, it is striking that it also did not pursue other available incremental interpretative avenues that would have cohered better with the previous incremental approach than the new ‘political and strategic issues’ criterion. 

5.3.  Missed opportunities for an incremental interpretation of the Treaty provisions

Even if not adopting a fully principled constitutional approach, KS and KD also did not exhaust further incremental interpretation. 

A first possibility would have been to read the scope of Articles 24(1) TEU, 275(1) TFEU narrowly by revisiting the extent towhich the CFSP is distinctive today. The Treaty merely states that the CFSP is ‘subject to specific rules and procedures.’ A narrow interpretation, read in conformity with Article 2 TEU, could treat CFSP specificity as procedural rather than constitutional, and therefore as insufficient to displace the foundational values and principles of the rule of law, effective judicial protection, and respect for fundamental rights, which after all also form part of the Union’s external relations acquis under Article 21(1) TEU. Nothing in the Treaties precludes an interpretation of Articles 24(1) TEU, 275(1) TFEU that preserves the applicability of these general principles to the CFSP.

A second possibility would have been to continue with the incremental expansion of the exceptions in Article 275(2) TFEU. The exception of ‘restrictive measures against natural and or legal persons’ could be decoupled from its technical meaning (measures adopted under the CFSP procedures) as expressing just one example of a wider principle allowing for a fundamental rights review. The Commission had put forward a similar argument already in Opinion 2/13, namely, to consider a Council decision in the CFSP which conflicts with fundamental rights as such as a ‘restrictive measure’.[84]

Both incremental interpretative approaches could have been supported by a range of further interpretive methods and arguments. An argument based on the historical intent of the drafters could be used to identify a gap in the current Treaties that can be filled by interpretation, including through general principles of EU law. At the time of drafting of the exclusion clauses in the Treaty of Maastricht 1992, the scale of CFSP activities, and hence potential to impact individual rights today, could not have been foreseen.[85] Although the Lisbon Treaty maintained the exclusion of jurisdiction in the CFSP despite abolishing the pillar structure, this was because the primary area of concern about fundamental-rights sensitive CFSP actions at the time were the terrorist sanctions regimes which were used increasingly as a policy response to the 9/11 attacks and beyond. The exceptions in Article 275(2) TFEU responded to that concern as required by the state of evolution of the CFSP at the time, but cannot be read as reflecting an intention to exclude other scenarios where the CFSP might conflict with fundamental rights.[86]

A teleological argument might point to the fact that since the Lisbon Treaty abolished the pillar structure and integrated the CFSP within the single EU legal order, the rationale for a broad exclusion of jurisdiction is no longer valid. The evolution of the CFSP with an increasingly operational nature of missions, and the growing role of EU institutions in their management all suggest that the CFSP cannot be treated as a domain structurally insulated from judicial review. In holding that fundamental rights cannot themselves confer jurisdiction, the Court side-stepped the question whether the exclusions of jurisdiction in an entire policy domain is compatible with the right to effective judicial protection in Article 47 EUCFR. In finding that Article 47 EUCFR is not an absolute right, it avoided the question whether the total and a priori exclusion of jurisdiction in an entire policy area goes to the core of the right.[87] The discussion to what extent the European Court of Human Rights as an international court allows for the exclusion of jurisdiction under the ECHR is, to an extent (beyond the ability of the EU to accede to the ECHR), besides the point. The case law of the European Court of Human Rights is still unsettled.[88] And the real and primary question is: what is or should be the appropriate level of protection in the EU as a constitutional legal order. For that, the ECHR’s minimum standard should not determine conclusively the level of protection in the EU. The CJEU acts functionally equivalent to a national court. As such it strives or should strive for a higher level of protection than an international minimum standard (Article 52(3) EUCFR). 

Such a teleological approach would have allowed the Court to hold that, where individual rights are engaged, there should be a strong presumption of judicial review. This would align CFSP judicial review with the EU’s broader fundamental rights jurisprudence, including in Les Verts and Kadi,[89] which emphasise that no EU activity can escape the rule of law, with the post-Lisbon dissolution of the pillar structure, and the factual evolution of the CFSP.

It would also have been in line with a trend in the evolution of national law in the context of foreign relations. While this cannot be explored in detail here, foreign policy has long been approached as an ‘exceptional’ area of policy,[90] dominated by, or even exclusively reserved to, the executive – keeping parliaments and the courts out of this policy area. Legal doctrines of non-justiciability and the separation of powers prevented historically the involvement of courts, such as the Royal prerogative in the UK. However, in a comparative perspective, the intersection of foreign policy with fundamental and human rights has led to significant changes. These are frequently summarised as a trend of ‘normalisation’ of foreign policy – meaning the same general rules apply as with any other policy area.[91] For example, in the UK legal order, the legal fallout of the Iraq war of 2003 has led to a major change in how fundamental rights are considered to apply in foreign policy, even in the context of military action as the prime area of executive exceptionalism. It is now recognised that even military action is no rights-free zone.[92] This had been recognised in other jurisdictions already previously.[93] However, this does not mean that specific needs of the policy area cannot be accommodated. Accommodation of the context and the discretionary nature of foreign policy choices need not occur through an a priori exclusion of other constitutional actors under a doctrine of non-justiciability. Rather such considerations can be reflected in the interpretation of procedural and substantive obligations, and the weight accorded to competing different interests in judicial balancing exercises.[94]

6.   The Road Not Taken: Missed Opportunities for General Principles, the Rule of Law and Constitutional Resilience

Substantively, the case of KS and KD turns on general principles: the rule of law, fundamental rights and the right to an effective remedy underpin the Court’s extension of jurisdiction in the CFSP. But explicit references to general principles are conspicuouslyabsent in the Court’s reasoning. This is despite being a core element of the Union’s constitutional framework and despite their methodological relevance for filling gaps, promoting coherence across policy areas and legal orders and for enhancing legitimacy when developing the EU legal order. All these considerations were relevant in the case of KS and KD. This means an opportunity was missed for bolstering the coherence and legitimacy of the Court’s conclusions in the specific case of KS and KD and for the broader constitutional potential of the case – as well as for general principles as a tool in the EU legal order.

This methodological omission matters. How constitutional adjudication and reasoning is framed, shapes the scope of judicial review and the effects of the judgment. General principles are not merely substantive norms but structural elements with several important characteristics.

General principles of EU law are an independent source of primary law, forming part of the ‘law’ of the EU, as referred to in Articles 19(1) TEU and 263(2) TFEU which gives them constitutional legitimacy.[95] They have fulfilled the functions of guiding interpretation to further the coherence of EU law, filling gaps in the EU legal order, and providing grounds for legality review and claims of liability.[96] Particularly noteworthy is the role they have played across legal regimes and orders, both in furthering intra-systemic coherence within the EU legal order (across policies) and between the EU and the legal orders of the Member States and international law (across legal orders), and in constructing and constitutionalising the EU legal order itself.[97] This has in part to do with the way they are created, as the ‘synthesis’[98] of an evaluative and inductive-comparative approach, drawing on the constitutional traditions of the Member States[99] which has a legitimacy enhancing effect. It is worth noting that, since KS and KD has been decided, the Court relied in Commission v Poland (ultra vires review) precisely on general principles – the general principle of effective judicial protection, reflected in Article 47 EUCFR – to support its reasoning across legal orders. Drawing on the common constitutional traditions of the Member States, the Court rejected Poland’s argument that certain EU acts were ultra vires and infringed Polish constitutional identity. It emphasised that Article 2 TEU articulates not only EU values but also the identity of the EU as a common legal order, requiring compliance of both the EU and the Member States.[100] A similar line of reasoning could have been employed to overcome the restriction of jurisdiction in the CFSP.

In the hierarchy of norms in EU law, general principles enjoy the status of primary law. The Court referred to some general principles having constitutional status,[101] which could even suggest a higher status within primary law.[102] Last but not least, the existence of a general principle goes hand in hand with its enforcement and, thus, access to judicial remedies, e.g. as grounds for legality review and damages actions. Recognising these characteristics would have provided a clearer methodological foundation for the Court’s reasoning, bolstering the legitimacy of the judgment and reinforcing the constitutional coherence of the EU legal order. They might, thus, have facilitated taking a more principled approach.

6.1.  Informing interpretation and furthering coherence

General principles act as interpretative tools to resolve tensions within primary law. Through interpretation in conformity with general principles, textual specificity may be reconciled with systemic constitutional requirements. A specific example for such interpretation discussed above, would have been a narrower reading of Article 24(1) TEU by interrogating the actual distinctiveness of the CFSP and the meaning of ‘specific rules and procedures.’ General principles could have supported a principled interpretationguided by Article 2 TEU values and the external relations acquis in Article 21(1) TEU. An example is the interpretation of national constitutional identity in Article 4(2) TFEU through the values of Article 2 TEU.[103] Such an interpretation grounded in general principles of law would have had added value over just applying the EU’s constitutional principles qua Treaty norms.

One of the features of general principles is their cross-cutting quality and presumption of applicability both in a horizontal and vertical dimension.[104] They apply horizontally within the EU across all policy areas, irrespective of the regulatory techniques or institutional balances that govern specific domains. Thus, reasoning based on general principles could have added further weight to a constitutionally principled approach derived from Articles 2, 19 and 21 TEU: that the rule of law, fundamental rights and judicial protection apply even in areas characterised by exceptionalism such as the CFSP. General principles could have provided a more robust framework for conceptualising the tension between the exclusion of judicial review in the CFSP and fundamental rights and the rule of law. 

General principles also derive their legitimacy in part from the legal orders of the Member States and are applicable in the vertical dimension. They cut across the legal orders of the EU and its Member States. The cross-cutting nature of general principles and their substantive origin in the Member States’ legal orders could have been used to add legitimacy and weight to interpretating Treaty norms consistently with the values of Article 2 TEU qua general principles.[105] This could have also widened the perspective to comparative considerations, e.g. the extent to which Member States today allow for judicial review both in a CFSP context and in foreign relations generally.

Rather than presenting the clash as a textual conflict between opposing Treaty provisions which rank formally at the same level, the Court might also have broken new ground by recognising explicitly a clash between Treaty norms and unwritten general principles of constitutional stature that were originally derived from the Member States’ constitutional traditions, thus emphasising the common ground and significance of the norms in a ‘common legal order’,[106] adding weight to the application across policies in the horizontal dimension and across legal orders in the vertical dimension.

6.2.  Filling gaps

Considering the exclusion of jurisdiction in the CFSP from the vantage point of general principles opens the perspective of potential gaps in the EU legal order – and how these might be filled. Although the issue in KS and KD looks prima facie like a conflict between two sets of written Treaty norms, approaching the case from the angle of general principles raises the questions: is there a gap and how is it to be filled? 

As discussed above,[107] gaps in judicial protection have indeed arisen in the EU legal order when considering its evolution and contextual factors: factual and legal developments which led to an intensification of CFSP actions since the Maastricht Treaty mean that the rationale for the exclusion of jurisdiction in the CFSP no longer matches the present-day circumstances. But the Court did not situate its interpretation within the evolving context of EU external action, developments in international law, and shifts in domestic constitutional practice.[108] The expansion of CFSP activities with individual rights implications has outpaced the limits on accountability retained in the Treaties. At the same time, domestic courts increasingly adjudicate foreign policy matters.[109]Against this backdrop, a categorical exclusion of entire policy fields from judicial review is anachronistic. General principles could have served as the tool to bridge this structural gap, aligning the CFSP framework with contemporary accountability standards and ensuring constitutional coherence.

The exclusion of judicial review in the CFSP in the wording of the Treaties is an example of the still relatively immature nature of the EU legal order in this respect. The same is true for the lack of clearer constitutional hierarchies between Treaty provisions and in EU primary law more broadly. This is reflected in gaps and points to a need for a clearer constitutional framework and greater degree of constitutionalisation of the EU legal order. As a still maturing constitutional order, the EU legal order has a heightened need for unwritten norms, such as general principles of law, to facilitate a dynamic dialogue with external legal orders. Opening it to comparative and international human rights law experiences may contribute to filling normative gaps, reinforcing both its coherence and its legitimacy.

As discussed above, general principles could have supported filling the gap in judicial protection, particularly by adding a general fundamental rights ‘exception’ to the restrictive measures exception in Article 275(2) TFEU.[110] Such an approach would have organically incorporated judicial review of CFSP acts which impact on fundamental rights without introducing a nebulous ‘political and strategic issues’ criterion.

6.3.  Developing constitutional hierarchy in the EU

A further missed opportunity concerns the development of a substantive constitutional hierarchy, to further constitutionalise the EU legal order. Formally, all Treaty provisions of the TEU and TFEU[111] and general principles share equal status. But this is problematic, as any Treaty rule may be pitched against formally equal-ranking Treaty provisions – as EU fundamental values were pitched against the exclusion of jurisdiction in the CFSP. The EU legal order already recognises substantive constitutional hierarchies in its language in Article 2 and 3(5) and 21 TEU and structurally in the EU accession criteria and conditions for suspension for membership rights.[112] Until recently, the Kadi I case has been the clearest expression of this in according a higher rank to the foundational principles of liberty, democracy, and human rights over other Treaty norms.[113] More recent jurisprudence, such as the fleshing out of the distinction of specific and essential characteristics of autonomy in Opinion 1/17,[114] the Budget Conditionality Regulation judgments[115] and, most recently, in Commission v Poland (ultra vires review)[116] and Commission v Hungary (LGBTI+ rights),[117] affirm that Article 2 TEU values and general principles form the constitutional core of the EU legal order.[118]

Had the Court explicitly articulated such a hierarchy of a constitutional core in KS and KD, it could have clarified the relative weight to be accorded to the specific characteristics of the CFSP on the one hand and the Union’s foundational constitutional principles as essential characteristics[119] on the other hand, thereby requiring the former to be interpretated in the light of the latter. This would have strengthened the constitutional logic of the judgment and may also contribute to building constitutional resilience[120] of the EU legal order against rule-of-law backsliding. Recognising the direct enforceability of Article 2 TEU in Commission v Hungary (LGBTI+ rights)[121] may provide the basis for the further development of substantive normative hierarchy in the EU legal order in the future.

6.4.  Implications for the rule of law and constitutional resilience

By not engaging with the methodological and structural role of general principles, KS and KD missed an opportunity to reinforce the EU’s rule-of-law architecture. A more principled approach, developing the core of constitutional principles in the hierarchy of EU law, grounded in general principles, would have clarified the constitutional limits of political discretion, provided a clearer and broader foundation for judicial protection, and contributed to a more coherent EU legal order overall. Additionally, pointing to multiple legal bases of the same norms and principles can enhance the reasoning and legitimacy of the outcome, even if the content of the norm is identical.[122]

By drawing on multiple sources of authority, the Court could have articulated the EU’s foundational values as constitutional principles of a higher normative rank within the EU legal order. Such an approach would not only contribute to strengthening the constitutional resilience of the Union itself, but also of the Member States by embedding those values more firmly within the broader European constitutional framework.[123] Embedding the constitutional values of the EU in a multi-layered human rights protection through EU accession to the ECHR would further contribute to building constitutional resilience. It can only be hoped that KS and KD will be applied in a way to have eliminated the remaining obstacle[124] – and that the opportunity for EU accession has not passed in the meantime.

Given the increasing contestation of EU primacy, foundational values and fundamental rights more broadly within certain Member States, the articulation of a clear constitutional hierarchy, rooted in general principles, holds the potential not only to resolve conflicts but to differentiate legitimate from illiberal constitutional arguments. A robust constitutional debate with EU Member States about the EU’s core values needs to be distinguishable from illiberal resistance which uses formalistic challenges to primacy of EU law to undermine EU core values. The missed opportunities in KS and KD thus resonate well beyond CFSP: they speak to the ongoing project of constitutionalising the EU’s internal legal order as such and radiating rule-of-law commitments across legal orders.

This makes it particularly salient that the direct and transnational potential of general principles for the rule of law was not harnessed to provide a basis for potentially influencing other legal orders, first and foremost within the EU, but also beyond. General principles are also a tool of transnational law-making: they are an opening device by which courts of different legal orders may directly or indirectly communicate, both internally in relation to EU Member States and externally, projecting to the wider world. Against this background, the limited methodological engagement with general principles in KS and KD represents a further missed opportunity.