A/HRC/12/48 page 76 These protections apply to all persons in the power of a party to the conflict “who do not benefit from more favourable treatment” under the Geneva Conventions and its Protocols. 285. The foregoing customary and conventional humanitarian rules are relevant to the investigation of the events that occurred in connection with the military operations of December 2008 and January 2009. C. International criminal law 286. International criminal law has become a necessary instrument for the enforcement of IHL and IHRL. Criminal proceedings and sanctions have a deterrent function and offer a measure of justice for the victims of violations. The international community increasingly looks to criminal justice as an effective mechanism of accountability and justice in the face of abuse and impunity. The Mission regards the rules and definitions of international criminal law as crucial to the fulfilment of its mandate to look at all violations of IHL and IHRL by all parties to the conflict. 287. Crimes under international law are defined in treaties and also in customary international law. Violations of fundamental humanitarian rules applicable in all types of conflict entail individual criminal responsibility under customary law.171 They encompass crimes against humanity, war crimes and genocide. Other crimes not necessarily committed as a war crime or crime against humanity are torture and enforced disappearance. 288. The four Geneva Conventions of 1949 establish a regime of enforcement through the definition of grave breaches of some of their provisions relating to protected persons. Grave breaches are premised on the importance of the value under attack and the seriousness of the act or omission that constitutes the breach. Article 147 of the Fourth Geneva Convention defines grave breaches as: … those involving any of the following acts, if committed against persons or property protected by the present Convention: wilful killing, torture or inhuman treatment, including biological experiments, wilfully causing great suffering or serious injury to body or health, unlawful deportation or transfer or unlawful confinement of a protected person, compelling a protected person to serve in the forces of a hostile Power, or wilfully depriving a protected person of the rights of fair and regular trial prescribed in the present Convention, taking of hostages and extensive destruction and appropriation of property, not justified by military necessity and carried out unlawfully and wantonly. 289. Article 146 requires States parties to enact any legislation necessary to provide effective penal sanctions for persons committing, or ordering to be committed, any of the listed grave breaches. They are under the obligation “to search for persons alleged to have committed, or to have ordered to be committed, such grave breaches, and shall bring such persons, regardless of their nationality, before its own courts.” Ibid., paras. 128 ff. In paragraph 134, the Appeals Chamber stated: “All of these factors confirm that customary international law imposes criminal liability for serious violations of common article 3, as supplemented by other general principles and rules on the protection of victims of internal armed conflict, and for breaching certain fundamental principles and rules regarding means and methods of combat in civil strife.” 171