the way in which it is complying with each measure ordered by the Court is essential to assess the status of compliance with the judgment as a whole.2 5. The obligation to comply with the decisions of the Court corresponds to a basic principle of the law on the international responsibility of the State, supported by international case law, according to which the States must comply with their international treaty obligations in good faith (pacta sunt servanda) and, as this Court has already indicated and as established in Article 27 of the 1969 Vienna Convention on the Law of Treaties, they may not invoke the provisions of its domestic law as justification for failure to assume the pre-established international responsibility. The treaty obligations of the States Parties are binding for all the powers and organs of the State.3 6. The States Parties to the Convention must ensure compliance with its provisions and their inherent effects (effet utile) within their respective domestic legal systems. This principle applies not only with regard to the substantive provisions of human rights treaties (that is, those that include provisions on the protected rights), but also with regard to procedural norms, such as those referring to compliance with the decisions of the Court. These obligations shall be interpreted and applied so that the protected guarantee is truly practical and effective, bearing in mind the special nature of human rights treaties.4 a) Obligation to investigate and to punish those responsible 7. Regarding the obligation to investigate and to punish those responsible for the disappearance and presumed death of the victims (fifth operative paragraph of the judgment on merits), the State reiterated its request that the Court not mention the information provided concerning the investigation of these facts in any public document. It indicated that “the investigation continues and measures are constantly being taken to explore all the alternatives that may lead to the identification, investigation and, as appropriate, punishment of those responsible.” Regarding the feasibility of the appeal for review of the criminal proceedings relating to this case, the State reiterated the information provided prior to the 2009 order (supra having seen paragraph 2), indicating that “there is no possibility that filing [it] would be successful.” 8. The representatives indicated that “the actions of the Prosecutor General’s Office since the end of 2009 and the beginning of 2010 reveal several activities that objectively reflect the interest and decision to advance the investigation,” and that this progress “must be accompanied by adequate protection for those who are participating in the criminal proceedings, because the witnesses remain afraid to testify. However, they stressed that the proceedings are still at the pre-trial stage and expressed their concern owing to the lack of procedural activity since April 22, 2010, which has resulted in non-compliance with the obligation to respect the principle of reasonable time in the investigations; consequently, they asked that the investigation be reactivated as soon as possible. In addition, they 2 Cf. Case of Barrios Altos v. Peru. Monitoring compliance with judgment. Order of the Inter-American Court of Human Rights of September 22, 2005, seventh considering paragraph, and Case of Castañeda Gutman v. Mexico. Monitoring compliance with judgment. Order of the Inter-American Court of Human Rights of January 18, 2012, sixth considering paragraph. 3 Cf. International Responsibility for the Promulgation and Enforcement of Laws in Violation of the Convention (Arts. 1 and 2 of the American Convention on Human Rights). Advisory Opinion OC-14/94 of December 9, 1994. Series A No. 14, para. 35, and Case of Castañeda Gutman, supra note 2, fourth considering paragraph. 4 Cf. Case of Ivcher Bronstein v. Peru. Competence. Judgment of September 24, 1999, Series C No. 54, para. 37; and Case of Gutiérrez Soler v. Colombia, supra note 1, fourth considering paragraph. 3