International law-making has been expanding enormously. More than 50,000 treaties have been concluded since the United Nations began, and Australia is now a party to over 900 conventions and treaties. International law affects our understanding of human rights, criminal law, the environment, international trade, intellectual property and industrial relations. Over the past forty years many nations have recognised their growing interdependence, as international law has become more involved in their structures and workings. The old focus upon external relations between nations has broadened to include events within nations. International bodies, such as the UN Human Rights Committee, now scrutinise the conformity of Australian law with international norms. Australian courts have consequently given greater recognition to international law, even in cases where Australia has not yet implemented the relevant treaty in domestic law. Federal Parliament is now able to use international treaties as a basis for domestic law, and this has dramatically affected the traditional division of legislative authority between state and federal spaces. "International Law and Australian Federalism" is a collection of essays by prominent Australian academics, government lawyers and judges in the fields of international and constitutional law. It explores issues fundamental to the development of Australia's legal system. These issues must also concern policy makers in the political sphere, as we move towards a greater globalisation and closer international relations.