Quick questions on The External Affairs Power and Incorporation: WACE Year 12 Politics and Law

To make a treaty enforceable domestically, Parliament passes an Act that incorporates its terms. The Racial Discrimination Act 1975, for instance, implements the Convention on the Elimination of All Forms of Racial Discrimination, and various environmental and human rights Acts implement other conventions. This legislation is what individuals and courts actually rely on. Without it, a treaty obligation may still influence the law indirectly, for example by informing the interpretation of ambiguous statutes or as a legitimate expectation, but it does not directly bind.

The constitutional basis for implementing treaties is the external affairs power in section 51(xxix), which lets the Commonwealth make laws with respect to external affairs. The High Court has interpreted this power broadly to include implementing Australia's international treaty obligations. This is significant for federalism: a treaty can concern a subject that would otherwise be a residual state power, yet a Commonwealth law implementing it is valid under the external affairs power. The power therefore lets the Commonwealth reach into areas like the environment and human rights through the treaty route.

The defining authority is the Commonwealth v Tasmania (1983), the Tasmanian Dam Case. Tasmania planned to dam a river in a World Heritage area; the Commonwealth, relying on the World Heritage Convention, legislated to stop it. The High Court upheld the Commonwealth law as a valid exercise of the external affairs power, holding that the Commonwealth could legislate to give effect to a genuine treaty obligation even on a matter (land use) normally within state control. There are limits: the law must give effect to a bona fide treaty obligation and be reasonably appropriate to that end.