This article offers a reconstruction of how the Court of Justice of the European Union (EU) justifies the territorial scope of application of EU law. Scholarship on this issue tends to advocate for an expansive projection of EU norms in the pursuit of global values, subject to the external limits of public international law. This article will develop a critique of this approach by pointing to its underlying assumptions as to the territorial dimension of the EU's rule, the insoluble practical issues that it leads to, and the need to consider differently the EU's spatial identity and relation to the wider world. It will also be argued that, in fact, other case law sometimes already reflects an alternative vision, by imagining the EU implicitly, not as a ‘global actor’ promoting universal values, but as a concretely situated and spatially bounded community. It will be shown that this is so with the methodological help of private international law, and in particular three doctrines that are traditional to this discipline—the localisation of cross-border relations, international imperativeness, and the public policy exception. This will ultimately allow for a more sophisticated understanding of the EU's territory to emerge—irreducible to the physical coordinates of its acts of intervention, or the mere sum of the physical spaces under Member State sovereignty, but as a distinct space of social relations, informed and delineated by the particular axiology and structure of the EU legal system.

Cooperation with third countries on readmission has occupied an increasingly prominent place in the EU's migration management strategy. The EU and its Member States have progressively concluded an extensive set of bilateral and multilateral, binding and non-binding, cooperation instruments on readmission. This proliferation questions the field's coherence with the principle of sincere cooperation, governing the interplay between the Union's and Member States’ action. By taking this principle as a benchmark, the article highlights the ineffective nature of the current ‘unprincipled’ pursuit of readmission goals. It also demonstrates that sincere cooperation—if read together with subsidiarity—does not necessarily favour the Union's international action, to the detriment of the Member States’. Rather, it requires a good faith effort to identify, and stand by, the most effective level of action.

This Article argues that the cooperation obligations of the Member States under EU law are best understood as forming part of an overall duty of EU loyalty and elaborates on the consequences of framing it in this way. EU loyalty legally requires Member States to make the common EU interest their own. The Article further demonstrates that EU loyalty is more relevant and more stringently applied in EU external relations than within the EU legal order. Loyalty obligations of the Member States reach into the future, extend to hypothetical situations, and are at a comparatively high level of abstraction aimed to protect the Union's ability to act effectively on the international plane. This limits Member States’ margin of manoeuvre, including when they take unilateral external action within the realm of their retained national competences. The Article explains that this may be functionally justified by the high stakes of non-concerted external action. However, and in particular with the EU's increased external powers and the ever-growing relevance of international cooperation, the stringent application of cooperation requirements should be (better) explicated and justified.

In the European Union, private international law has almost exclusively been developed through the adoption of internal acts (particularly EU Regulations) in the pursuit of internal goals (principally, enhancing the efficient functioning of the internal market, and more recently and broadly the construction of an area of freedom, security and justice). This focus has and must come under challenge in light of two developments. The first is the apparent establishment of EU exclusive external competence in the field of private international law, creating the opportunity for external action by the EU. The second is the increased recognition that internal action by the EU has external effects, which should be viewed not merely as incidental but also as potentially instruments of external policy. In conjunction, these developments demand consideration of what role private international law could and should play as part of EU external relations. This article critically examines a range of possible techniques which might be adopted in relation to this new external dimension of EU private international law. These methods are not necessarily unique to private international law or the EU, and thus this article also provides a case study of the range of legal techniques which can be used by international actors to project policies externally.

Direct effect of international agreements – WTO – Current jurisprudence and theories – Implications for separation of powers and checks and balances – Justiciability – Criticism of current standards: precision and reciprocity – Reversal of dual concept in EU external relations

International law in constitutional change of EU – Rigidity of amendment – EU amending and accession treaties not reviewable – International law in internal development of Union law – Conventions/treaties by member states jointly – Acts of the representatives of the governments – International law in the agreements with third states – Exportation of legal rules – Conditionality policies – Legislating through international agreements