100 United Nations Convention Against Torture and its Optional Protocol of the non-​refoulement principle. Torture is one of the most serious human rights violations, and complicity or participation in torture, which includes sending a person to a country despite a risk of torture there, constitutes a severe violation of the Convention. 3  The principle of non-​refoulement is absolute and affords protection to every person regardless of the threat he or she may pose to the national security of the sending country and regardless of whether he or she has committed serious crimes. No balancing of interests is permitted. In contrast to the Refugee Convention of 1951, Article 3 CAT guarantees an absolute right which is not subject to any exclusion or limitation clause. Thus persons who might, for instance, for national security reasons not be eligible for asylum are equally protected. 4  In contrast to the principle of non-​refoulement as developed by the European Court of Human Rights (ECtHR) and the UN Human Rights Committee (HRC) on the basis of Article 3 ECHR and Article 7 CCPR, Article 3 CAT only applies to torture in the sense of Article 1 CAT, but, owing to the insistence of the US during the drafting, not to other forms of cruel, inhuman or degrading treatment. However, other ill-​treatment, not amounting to torture, is not irrelevant in the context of Article 3: the infliction of other ill-​treatment is an indication of a torture risk8 and States parties should in their assessment of torture risk consider whether the risk of other ill-​treatment ‘could likely change so as to constitute torture’.9 Apart from that, the Committee has in its State reporting procedure urged States parties not to return persons to situations where they might run the risk of torture or cruel, inhuman or degrading treatment or punishment.10 5  States parties must not send persons to States where the risk of torture emanates from non-​State actors who enjoy impunity either because the State fails to exert due diligence or because the State is not or only partially in control of its territory. 6  When methods of corporal punishment or the methods of implementing a death penalty as per national laws in the receiving State reach a threshold where they amount to torture, States parties are prohibited from returning persons to States where they might receive sentences imposing such treatment. 7  Although the text of Article 3 only speaks of expulsion, refoulement, and extradition, this provision covers all forms of obligatory departure of a human being (aliens as well as citizens) from one jurisdiction to another, including forms of ordinary or extraordinary ‘rendition’, as practised in the fight against global terrorism. Even the transfer of a suspected terrorist from the US detention centre of Abu Ghraib to another detention centre in Iraq under the jurisdiction of the Iraqi Government must be assessed in relation to the non-​refoulement principle. Similarly, the Committee cautions against requesting and accepting diplomatic assurances from States with a known record of torture. Diplomatic assurances do not absolve a sending State party from its obligations under Article 3, and from carrying out the risk assessment mandated by the non-​refoulement principle. 8  In order to guarantee the principle of non-​refoulement, Article 3 also demands preventive measures, in particular legislative, administrative, and judicial measures against possible violations.11 Such measures include inter alia procedural rights of the person 9   CAT/​C/​GC/​4 (n 2) para  28.   ibid, para 16.   See eg CAT, ‘Concluding Observations: Jordan’ (25 May 2010) UN Doc CAT/​C/​JOR/​CO/​2, para 23; CAT, ‘Concluding Observations: Guinea’ (2014) UN Doc CAT/​C/​GIN/​CO/​1, para 24. 11   See CAT/​C/​GC/​4 (n 2) para 18. 8 10 Ammer/Schuechner