A Stronger Role for Customary International Law in Domestic Law
in Hilary Charlesworth et al (eds), The Fluid State: International Law and National Legal Systems (Sydney: Federation Press, 2005) 110–135 (ISBN 1862875685)
19 Pages Posted: 28 Sep 2015
Date Written: 2005
Over the past decade, the role of treaties in domestic law has become controversial and the subject of much debate. However, the relationship between domestic law and customary international law has been relatively neglected. This is certainly true in Australia for example, apart from the brief flurry of interest after the Federal Court's decision in Nulyarimma v Thompson ('Nulyarimma'). In this chapter, we consider the rationale for customary international law playing a role in domestic law and examine possibilities as to the kind of role it can play. In Part II we outline some justifications for using customary international law in domestic law, including arguments based upon the rule of law; the value of the international system; and achieving justice for individuals. We then canvass some barriers to the use of customary international law in a domestic context: problems of meaning and legitimacy; difficulties of proof; and judges' discomfort with customary international law. We conclude that there are good reasons for giving customary international law a place in domestic law, and that these reasons outweigh the valid concerns about the application of this body of principles. We then tum, in Part III, to outline several ways in which customary international law could play a stronger role in domestic law, using Australia as a case study. In particular, customary international law could be used in domestic law on the basis of legislative enactment; as part of the common law; as a limit on legislative power; as a tool in administrative law; or as an influence on constitutional interpretation.
Keywords: customary international law, domestic law, Australia
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