The EU is structurally engineered to dismantle national sovereignty, progressively transferring powers from sovereign states to an expanding supranational authority. The Treaties establish the objective of an “ever closer union,” while the principles of subsidiarity and sincere (loyal) cooperation, combined with the binding interpretive and enforcement authority of the CJEU, create mechanisms through which EU law can constrain national decision-making. National courts are also required, within the scope of EU law, to ensure the effectiveness and primacy of EU law and to follow the CJEU’s authoritative interpretation. This means that, wherever EU law applies, national courts are not free to treat domestic law as superior or interpret it in isolation: they must interpret national law, so far as possible, consistently with EU law, disapply any conflicting national provision, and give full effect to EU rules as authoritatively interpreted by the CJEU. In those fields, the primacy of EU law places national courts under a binding duty to uphold the Union legal order, even where doing so limits or overrides the application of domestic legislation.
The Commission further reflects this structure: Commissioners are not representatives of their respective nation-states but are required to act in the general interest of the Union, while the Commission holds the primary right of legislative initiative. Taken together, these institutional arrangements progressively shift areas of decision-making from the national to the supranational level, little by little,until, from this perspective, the cumulative process can amount to a profound erosion of national sovereignty.