29. Article XIII of the Inter-American Convention on Forced Disappearance of Persons, 26 in relation to Article 62 of the American Convention, establishes the power of the Court to examine matters related to compliance with the commitments made by the States parties to that instrument. 27 On this basis, and on that of the principle of non-retroactivity, codified in Article 28 of the 1969 Vienna Convention on the Law of Treaties, 28 the Court is competent to examine the alleged failure to comply with this instrument, which establishes specific obligations in relation to the phenomenon of enforced disappearance as of the date on which the defendant State accepted the jurisdiction 29 and of the entry into force of the said instrument for the State. 30. Furthermore, the same principle reveals that, from the time that a treaty enters into force, the States parties can be required to comply with the obligations it contains in relation to any act that is subsequent to that date. This corresponds to the principle of pacta sunt servanda, according to which “[e]very treaty in force is binding upon the parties to it and must be performed by them in good faith.” 30 In this regard, it is necessary to distinguish between instantaneous acts and acts of a continuing or permanent nature. The latter extend “over the entire period during which the act continues and is not in conformity with the international obligation.” 31 Owing to their characteristics, once the treaty enters into force, those continuing or permanent acts which persist after that date can generate international obligations for the State party, without this signifying a violation of the principle of the non-retroactivity of treaties. 32 31. This type of act includes the enforced disappearance of persons, the continuing or permanent nature of which has been recognized repeatedly by international human rights law. 33 In such cases, the perpetration of the disappearance begins with the deprivation of the person’s liberty and the ensuing lack of information on his fate, and remains until the whereabouts of the disappeared person are known and the facts have been clarified. Indeed, according to this Court’s consistent case law, the relevant factor for the conclusion of an enforced disappearance is the 26 This article establishes that: “[f]or the purposes of this Convention, the processing of petitions or communications presented to the Inter-American Commission on Human Rights alleging the forced disappearance of persons shall be subject to the procedures established in the American Convention on Human Rights and in the Statute and Regulations of the InterAmerican Commission on Human Rights and the Statute and Rules of Procedure of the Inter-American Court of Human Rights, including the provisions on precautionary measures. 27 Cf. Case of Radilla Pacheco v. Mexico. Preliminary objections, merits, reparations and costs. Judgment of November 23, 2009. Series C No. 209, para. 303. 28 Article 28 of the Vienna Convention on the Law of Treaties establishes that “[u]nless a different intention appears from the treaty or is otherwise established, its provisions do not bind a party in relation to any act or fact which took place or any situation which ceased to exist before the date of the entry into force of the treaty with respect to that party.” 29 Cf. Case of González Medina and family members v. Dominican Republic. Preliminary objections, merits, reparations and costs. Judgment of February 27, 2012. Series C No. 240, para. 53. 30 Article 26 of the Vienna Convention on the Law of Treaties. Similarly, cf. Case of Loayza Tamayo. Compliance with judgment. Order issued by the Inter-American Court on November 17, 1999. Series C No. 60, para. 7, and Case of Radilla Pacheco v. Mexico, supra, para. 20. 31 Article 14 of the draft Articles on Responsibility of States for Internationally Wrongful Acts. In this regard, cf. James Crawford, The International Law Commission's Articles on State Responsibility: Introduction, Text and Commentaries, Cambridge, University Press, 2002. Also, cf. Case of Blake v. Guatemala. Preliminary objections. Judgment of July 2, 1996. Series C No. 27, para. 39, and Case of Radilla Pacheco v. Mexico, supra, para. 22. 32 Cf. Case of Radilla Pacheco v. Mexico, supra, para. 22. 33 Cf. Case of Velásquez Rodríguez v. Honduras. Merits. Judgment of July 29, 1988. Series C No. 4, para. 155, and Case of Gudiel Álvarez et al. v. Guatemala. Interpretation of the judgment on merits, reparations and costs. Judgment of August 19, 2013. Series C No. 262, para. 64. The European Court of Human Rights has also considered the continuing or permanent nature of the enforced disappearance of persons. Cf. ECHR, Case of Cyprus v. Turkey, Application No. 25781/94, Judgment of 10 May 2001, paras. 136, 150 and 158, and Case of Loizidou v. Turkey, Application No. 15318/89, Judgment of 18 December 1996, para. 41. 14