3 5. That the obligation to comply with the Court decisions corresponds to a basic legal principle regarding the international liability of the State, supported by the international case law, by means of which every treaty in force is binding upon the parties to it and must be performed by them in good faith (pacta sunt servanda) and, as already pointed out by the Court and as set forth by Article 27 of the Vienna Convention on the Law of Treaties of 1969, a party may not invoke the provisions of its internal law as justification for its failure to perform a treaty. The conventional duties of the States Parties are binding for all of the State powers and organs.2 6. That the States Parties to the Convention must guarantee the fulfillment of the international provisions and their own effects (effet utile) within the context of their respective internal legal systems. This principle applies not only regarding substantive rules of human rights treaties (that is to say, those which include provisions on the protected rights) but also with regard to procedural rules as those referring to the fulfillment of the Court’s decisions. These obligations must be interpreted and applied so that the protected guarantee is truly practical and 3 efficient, considering the special nature of human rights treaties. * * * 7. That in the Decision of September 22, 2005, the Court requested the State to submit updated information regarding the payment of the compensation to Mr. Martín León-Lunazco, son of victim Máximo León-León (operative paragraph 2.c of the reparations Judgment rendered on November 30, 2001), and to refer to the arrearages interest generated by the late payment of compensations awarded to Cristina Ríos-Rojas, daughter of victim Manuel Isaías Ríos-Pérez, and Rocío Genoveva Rosales-Capillo, daughter of victim Alejandro Rosales-Alejandro (operative paragraph two “in fine” of the reparations Judgment rendered on November 30, 2001). 8. That the State failed to inform on the payment of the compensation to Mr. Martín León-Lunazco, son of victim Máximo León-León. On the other hand, in their brief of remarks of February 29, 2008, the representatives pointed out that, said obligation was still pending fulfillment. The Commission made no reference to this matter. 9. That the State did not inform on the payment of the interest in arrears as a consequence of the delay in the payment of the compensations to Cristina RíosRojas, daughter of deceased victim Manuel Isaías Ríos-Pérez, and to Rocío Genoveva 2 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. A Series No. 14, par. 35; Case of García-Asto and Ramírez-Rojas v. Peru. Monitoring Compliance with Judgment. Supra Note 2, Considering Clause No. six; and Case of Sawhoyamaxa Indigenous Community v. Paraguay. Monitoring of Compliance with Judgment. Supra Note 2, Considering Clause No. two. 2 Cf. Case of Yatama. Monitoring Compliance with Judgment. Order of the Inter-American Court of Human Rights dated November 29, 2006, Considering Clause No. six; Case of Bámaca-Velásquez. Monitoring Compliance with Judgment, supra note 1, Considering Clause No. six; and Case of the “Five Pensioners”, supra note 1, Considering Clause No. eight. 3 Cf. Case of Ivcher Bronstein v. Peru. Jurisdiction. Judgment of September 24, 1999. C Series No. 54, par. 37; Case of Gómez-Palomino v. Peru. Monitoring Compliance with Judgment. Decision of the Court dated October 18, 2007, Considering Clause No. four; and Case of Sawhoyamaxa Indigenous Community v. Paraguay. Monitoring of Compliance with Judgment. Supra Note 2, Considering Clause No. five.