parties.” To this end, the States must ensure implementation of the Court’s rulings at the domestic level.1 4. 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 jurisprudence, under which States are required to comply with their international treaty obligations in good faith (pacta sunt servanda) and, as this Court has previously indicated and as established in Article 27 of the 1969 Vienna Convention on the Law of Treaties, a party may not invoke the provisions of its internal law as justification for its failure to perform a treaty.2 The treaty obligations of the States Parties are binding on all the powers and organs of the State.3 5. States Parties to the Convention must ensure compliance with its provisions and their inherent effects (effet utile) within their domestic laws. This principle applies not only with regard to the substantive provisions of human rights treaties (that is, those which contain provisions concerning 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) Regarding the obligation to investigate and to conduct impartial and effective judicial proceedings in relation to the three forced disappearances that occurred in this case, which lead to clarifying the truth of the facts and the punishment of those responsible (sixth operative paragraph of the judgment) 6. The State reported that, following the conclusion of the criminal proceedings against two defendants before the Third Trial Court of the Criminal Judicial Circuit of Vargas State, with regard to the disappearance of Oscar José Blanco Romero, judgment was handed down sentencing one of the defendants to 15 years’ imprisonment for the crime of forced disappearance of persons established in article 180-A of the Criminal Code, and designating the then Directorate of Intelligence and Prevention Services (DISIP) as the place of detention, and acquitting the other defendant. The State also indicated that “regarding this decision, it is hoped that the Public Prosecution Service will file an appeal against the acquittal.” 7. Regarding the case of Oscar José Blanco Romero, the representatives reported that the judgment of the Third Trial Court of the Criminal Judicial Circuit of Vargas State of June 5, 2009,5 was published on August 14, 2009; and an appeal was filed against it 1 Cf. Case of Baena Ricardo et al. Competence. Judgment of November 28, 2003. Series C No. 104, para. 60, and Case of the Yean and Bosico Girls v. Dominican Republic. Monitoring compliance with judgment. Order of the Inter-American Court of Human Rights of October 10, 2011, fourth considering paragraph. 2 Cf. International Responsibility for the Promulgation and Enforcement of Laws in Violation of the Convention (Arts. 1 and 2 American Convention on Human Rights). Advisory Opinion OC-14/94 of December 9, 1994. Series A No. 14, para. 35, and Case of the Yean and Bosico Girls v. Dominican Republic, supra note 1, fifth considering paragraph. 3 Cf. Case of Castillo Petruzzi et al. v. Peru. Monitoring compliance with judgment. Order of the InterAmerican Court of Human Rights of November 17, 1999, third considering paragraph, and Case of the Yean and Bosico Girls v. Dominican Republic, supra note 1, fifth considering paragraph. 4 Cf. Case of Ivcher Bronstein v. Peru. Competence. Judgment of the Inter-American Court of Human Rights of September 24, 1999. Series C No. 54, para. 37, and Case of the Yean and Bosico Girls v. Dominican Republic, supra note 1, sixth considering paragraph. 5 Regarding the decision of June 5, 2009, the representatives considered that “there is sufficient evidence of the connection that exists between [the person who was acquitted] and his role of control and 3