EU Loyalty and the Protection of Member States’ National Interests-A Mapping of the Law

In a general analysis on the protection of national interests of the Member States of the European Union, it is particularly apt to investigate their interplay with the principle of sincere cooperation. Enshrined in EU primary law, in particular in Article 4(3) TEU, that principle has evolved during the time into a veritable cornerstone of the EU legal order. Even though scholars have recently (re)started to pay attention to the loyalty principle and related implications, a general reflection on the role it plays—or should play—in considering/protecting the national interests of the Member States is still lacking. This contribution tries to fill the gap by charting the major possible interactions between loyalty and Member States’ national interests and the consequent legal trajectories. Our basic assumption is that of a progressive integration between the Member States’ and the Union’s legal orders—what will be called here the “Ever Closer Union Model”. According to this model, the gradual integration of the national and the EU legal orders will give rise to an expanding common legal area, which is where the loyalty principle and Member State interests interact. This chapter argues principally that in such a space the principle of loyalty plays a defining role in strengthening the protection of the common Union interests, securing in turn the related national interests of the Member States. This does not mean, however, that national interests cannot diverge from the EU common interests. Beyond the political tools, there are concrete legal avenues provided in the Treaties enabling the Member States to preserve their interests within the Union. Our analysis is completed by examining how the protection of Member State interests may play out in emergency scenarios, such as common policy crises, how a principle of solidarity may influence the operation of the principle of loyalty, and how loyalty towards the Union and the other Member States is affected by a State acceding to or leaving the EU.