Subsidiarity in the EU: Rhetoric or Reality? A Critical Assessment of Its Legal and Political Impact

Abstract This paper offers a critical assessment of the EU principle of subsidiarity, tracing its intellectual roots from nineteenth‑century Catholic social teaching through its codification in the Treaties and procedural reinforcement via the Lisbon-era Early Warning System (EWS). It first reconstructs subsidiarity’s theological and Christian Democratic origins and distinguishes it from competence delimitation and proportionality in the Union’s constitutional architecture. It then analyses the operation of Protocols No. 1 and 2, detailing the EWS’s yellow and orange card thresholds and the limited scope of parliamentary scrutiny over draft legislation. Drawing on over a decade of practice, including more than 1,200 reasoned opinions and only three yellow cards, and on key Court of Justice rulings that have never annulled an EU act solely on subsidiarity grounds, the paper demonstrates that the principle primarily serves as a symbolic deference that legitimizes continued supranational expansion. A comparative examination of United States federalism, with its enumerated powers and judicially enforced limits under the Commerce Clause and anti‑commandeering doctrine, highlights the EU’s confederal ambiguity and the weakness of subsidiarity as a justiciable safeguard. The paper concludes by advocating treaty reform toward explicit, federal‑style competence catalogues in core areas such as defense, fiscal policy, and foreign affairs, arguing that recent developments—from the Recovery and Resilience Facility to Ukraine‑related joint borrowing—already transcend subsidiarity and reveal a de facto federal trajectory that should be constitutionalized to ensure democratic legitimacy and geopolitical effectiveness.