On 31 October 2012 the Supreme Court of England and Wales handed down its judgment in Rahmatullah v Secretary of State for Foreign Affairs and Secretary of State for Defence. The case concerns an application for habeas corpus brought by a citizen of Pakistan originally detained by the United Kingdom in Iraq before being transferred into the custody of the United States. Rahmatullah addresses important issues concerning the extraterritorial reach of habeas corpus under English law in respect of persons held in the custody of a foreign State, as well as the international rule of law. The case may be considered a legal victory for persons detained without trial by the US in facilities thought to be beyond the reach of the courts. However, in reality any strength in the arm of the law is drained by the priority given to the conduct of foreign affairs, ‘forbidden territory’ for the courts, over the Court's ruling and the UK's obligations under international law. The case is examined in the light of similar jurisprudence from US and Australian courts.