Remedying Misaligned Norms in International and Constitutional Law: Investment Treaties, Property Rights and Proportionality

The enlargement of the scope of international law has led to more frequent overlaps in the substantive rules of domestic and international law. One such overlap is in the rules on expropriation, or the protection of property rights. This article argues that Australian constitutional law and international law are misaligned on the question of expropriation, with international law generally imposing a higher standard of protection compared to the Australian Constitution. The article contends that this misalignment matters, because it is irrational and discriminatory, and because it hinders Australia’s compliance with international law by increasing the complexity of official decision-making. The article then considers whether and how the misalignment can be remedied. Although a deliberate re-alignment faces difficulties, the article concludes that a form of alignment may organically emerge for other reasons, as both international tribunals and the Australian High Court take tentative steps towards the use of proportionality to resolve property rights claims.