Managing in a Federal System without an ‘Ultimate Arbiter’: Kompetenz- Kompetenz in the EU and the Ante-bellum United States ERIN DELANEY NYU School of Law ABSTRACT Although an ‘ultimate arbiter’ is generally accepted as a necessary element of a federation, emerging federal systems are often unable to agree on who should play the role. Legally, the debate surrounds the right to monitor the limits of federal and state competences – or the right to Kompetenz-Kompetenz. This article looks at how the early United States and the European Union managed without an ultimate arbiter and assesses the differing priorities of the two systems. It then examines how the Constitutional Treaty might change the delicate balance wrought by the European Court of Justice in Europe, and what lessons, if any, the early American experience might offer. KEY WORDS: USA, EU, European Court of Justice, US Supreme Court, kompetenz-kompetenz ‘Durable federal arrangements are possible only if two conditions hold: first, national [federal] forces must be ... restrained from infringing on the federal bargain. Second, provincial [state] temptations on federal arrangements must be checked ... by the application of legal rules enforced by an independent judiciary’ (Bednar et al., 2001: 226). This assessment by leading constitutional scholars encapsulates the difficulty inherent in federal systems – the relationship between the federal centre and the con- stituent parts. The federal challenge of ‘unity in diversity’ comes to the fore particularly in relation to the division of powers. If powers are divided, that division must be mon- itored. 1 But who should do the monitoring? Most scholars of federalism agree that com- petences should be delineated in a written constitution, with an independent court to act as the ultimate arbiter of the system (Proudhon, [1863] 1979; Dicey, 1959; Wheare, 1963; Sawer, 1969; Davis, 1978). 2 Determining the extent of federal or state compe- tences in practice requires interpretation of the constitution, which ‘involves Correspondence Address: NYU School of Law, New York, New York 10012, USA. Email: efd210@nyu.edu ISSN 1359-7566 print=1743-9434 online DOI: 10.1080=13597560500115584 # 2005 Taylor & Francis Group Ltd Regional and Federal Studies Vol. 15, No. 2, 225–244, June 2005