Domestic courts play an obvious role in controlling exercises of government power. On matters relating to the extraterritorial exercises of state power, international law provides a number of mechanisms domestic courts could make better use of, such as the principles of state responsibility. However, courts sometimes rely on outdated doctrines, such as comity and the act of state doctrine and this impedes meaningful engagement with international law. An example of this is the decision of the High Court of Australia in Plaintiff M68/2015 v Minister for Immigration and Border Protection (‘M68’),which can be contrasted with the decision in, for example, Moti v the Queen. In that context, this article is divided into three parts. So as to “set the scene”, background to the engagement of the High Court of Australia with international law is provided. By way of case study, the decision in M68 is then introduced. This article then draws on the Court’s engagement in M68 with the international law principle of state sovereignty, the principle of comity, and the act of state doctrine. This is done so as to make a broader argument that courts would be better equipped to regulate extraterritorial exercises of government power if they adopted a closer engagement with international law. In so doing, it is argued that the act of state doctrine and the principle of comity are outdated and contested ideas that are no longer useful or appropriate tools for domestic courts. Ultimately, it is suggested that if the High Court is to assert the international law principle of sovereignty, then it should, arguably, also look more broadly at principles of international law, including those on attribution.