B. Challenges to the absolute prohibition against torture The prohibition of torture and other cruel, inhuman or degrading treatment or punishment is absolute under international law. It is a peremptory norm—or a norm of jus cogens56—and is non-derogable even in states of emergency threatening the life of the nation under international and regional human rights treaties.57 The prohibition of torture and other cruel, inhuman or degrading treatment does not yield to the threat posed by terrorism or to the alleged danger posed by an individual to the security of a State.58 In practice, however, States have often adopted policies and methods to confront terrorism that, in effect, circumvent and undermine this absolute prohibition.59 For example, the use of torture and other cruel, inhuman or degrading treatment to elicit information from terrorist suspects is absolutely prohibited, as is the use in legal proceedings of evidence obtained by torture, whether at home or abroad, and of “secret evidence” put forward by prosecuting and other authorities in judicial proceedings, in violation of the principle of non-admissibility of evidence extracted by torture, contained inter alia in article 15 of the Convention against Torture.60 States’ policies that aim to exclude the application of human rights law to individuals outside their territory may effectively erode the absolute prohibition of torture, cruel and degrading treatment or punishment. According to the Human Rights Committee, the rights enshrined in the International Covenant on Civil and Political Rights apply to all persons who may be within a State party’s territory and to all persons subject to its jurisdiction (see above). This means that a State party must respect and ensure the rights laid down in the Covenant—including the absolute prohibition of torture—to anyone within its power or effective control, even if not situated within its territory. Similarly, the International Court of Justice has stated that, while the jurisdiction of States is primarily territorial, the rights enshrined in the Covenant extend “to acts done by a State in the exercise of its jurisdiction outside its own territory.”61 Regarding conditions of detention, practices such as the use of secret and incommunicado detention,62 as well as prolonged solitary confinement and similar measures aimed at causing stress, may amount to torture, cruel, inhuman or degrading treatment.63 32