CAT/C/USA/CO/2 page 5 19. Notwithstanding the State party’s statement that “[u]nder U.S. law, there is no derogation from the express statutory prohibition of torture” and that “[n]o circumstances whatsoever … may be invoked as a justification or defense to committing torture”, the Committee remains concerned at the absence of clear legal provisions ensuring that the Convention’s prohibition against torture is not derogated from under any circumstances, in particular since 11 September 2001 (arts. 2, 11 and 12). The State party should adopt clear legal provisions to implement the principle of absolute prohibition of torture in its domestic law without any possible derogation. Derogation from this principle is incompatible with paragraph 2 of article 2 of the Convention, and cannot limit criminal responsibility. The State party should also ensure that perpetrators of acts of torture are prosecuted and punished appropriately. The State party should also ensure that any interrogation rules, instructions or methods do not derogate from the principle of absolute prohibition of torture and that no doctrine under domestic law impedes the full criminal responsibility of perpetrators of acts of torture. The State party should promptly, thoroughly, and impartially investigate any responsibility of senior military and civilian officials authorizing, acquiescing or consenting, in any way, to acts of torture committed by their subordinates. 20. The Committee is concerned that the State party considers that the non-refoulement obligation, under article 3 of the Convention, does not extend to a person detained outside its territory. The Committee is also concerned by the State party’s rendition of suspects, without any judicial procedure, to States where they face a real risk of torture (art. 3). The State party should apply the non-refoulement guarantee to all detainees in its custody, cease the rendition of suspects, in particular by its intelligence agencies, to States where they face a real risk of torture, in order to comply with its obligations under article 3 of the Convention. The State party should always ensure that suspects have the possibility to challenge decisions of refoulement. 21. The Committee is concerned by the State party’s use of “diplomatic assurances”, or other kinds of guarantees, assuring that a person will not be tortured if expelled, returned, transferred or extradited to another State. The Committee is also concerned by the secrecy of such procedures including the absence of judicial scrutiny and the lack of monitoring mechanisms put in place to assess if the assurances have been honoured (art. 3). When determining the applicability of its non-refoulement obligations under article 3 of the Convention, the State party should only rely on “diplomatic assurances” in regard to States which do not systematically violate the Convention’s provisions, and after a thorough examination of the merits of each individual case. The State party should establish and implement clear procedures for obtaining such assurances, with adequate judicial mechanisms for review, and effective post-return