A/HRC/20/14 emphasizes that “the State has the right and duty to guarantee the security of all.”23 The State’s duty to uphold national security and its obligation to ensure the protection of the human rights of all those within its jurisdiction thus amount to a series of complementary, simultaneous and mutually reinforcing obligations. 19. It is axiomatic that States are under the obligation of an international law to put in place effective criminal law provisions to deter the incitement,24 preparation and commission of terrorist offences, supported by law-enforcement machinery for the prevention, suppression and sanctioning of breaches of such provisions.25 Defences available under national laws must be drafted with sufficient precision to ensure effective protection of the right to life and physical security. 26 20. The right to life under article 6 of the Covenant cannot be construed in such a way as to place States in the position of guarantor against every terrorist threat, as this would impose a disproportionate burden on the authorities. 27 However, in certain defined circumstances, public officials can come under a positive obligation to take operational measures to prevent a terrorist act from occurring.28 For such a positive operational obligation to arise, it must be established that (i) the authorities knew or ought to have known of (ii) the existence, at the relevant time, of a real and immediate (iii) risk to the life of an identified individual or group of individuals within its jurisdiction due to (iv) criminal acts of a third party, and that they failed to (v) take measures within the scope of their legal powers and available resources, and in conformity with their international obligations which, judged objectively and reasonably, might have been expected to avoid that risk. 29 21. In relation to requirement (i), States are required to establish effective mechanisms for identifying potential future threats of terrorist attack, to analyse the information with reasonable care, to reach an informed risk assessment and to take appropriate action. That action may include not only the disruption of threatened attacks by law enforcement agencies but also, where appropriate, the provision of information to the public. Many States have established dedicated institutions, mostly in the form of intelligence or security agencies, whose task is to detect potential national security threats, including terrorist threats, through the gathering and analysis of relevant information. The activities of those agencies must be fully compliant with international human rights law. 30 22. In relation to requirement (ii), authorities will not, in general, be in possession of all relevant facts in advance, and are therefore often obliged to plan counter-terrorism operations on the basis of incomplete factual hypotheses. State authorities are confronted on a daily basis with an immense amount of material about possible security threats. 31 Purely ex post facto assessments cannot be the sole basis for a finding of State responsibility for a violation of the right to life. They may however be of central importance when relevant authorities are called upon to conduct investigations for the 23 24 25 26 27 28 29 30 31 Inter-American Commission on Human Rights (IACHR), “Report on Terrorism and Human Rights,” para. 107, available at http://www.cidh.oas.org/Terrorism/Eng/toc.htm; see also IACtHR, NeiraAlegria et al. v. Peru, Judgment of 19 January 1995,. See Security Council resolutions 1372 (2001) and 1625 (2005). ECHR, Osman v. The United Kingdom, paras. 115-116. ECHR, A v. The United Kingdom, no. 100/1997/884/1096; X and Y v. The Netherlands, no. 8978/80. See footnote 25 above; see also ECHR, Branko Tomašić and Others v. Croatia, no. 46598/06, para. 50; ECHR, Giuliani and Gaggio v. Italy, no. 23458/02, Judgment of 24 March 2011, para. 245. See footnote 25. Ibid. See the compilation of good practices on legal and institutional frameworks for intelligence services and their oversight, promulgated by the former Special Rapporteur (A/HRC/14/46, paras. 9-50). See for example “Coroner’s Inquests into the London Bombings of 7 July 2005,” Report under rule 43 of the Coroner’s rules 1984, paras. 11-12. 7