53 humanity in the instant case, draws the attention to the fact that other crimes against humanity such as forced disappearance, torture, and genocide, among others, are not excluded from such amnesty. 117. The Court has confirmed on several occasions that: Under the law of nations, a customary law prescribes that a State that has signed an international agreement must introduce into its domestic laws whatever changes are needed to ensure execution of the obligations it has undertaken. This principle is universally valid and has been characterized in case law as an evident principle ("principe allant de soi"; Exchange of Greek and Turkish populations, avis consultatif, 1925, C.P.J.I., Series B, No. 10, p. 20). Accordingly, the American Convention stipulates that every State Party is to adapt its domestic laws to the provisions of that Convention, so as to 143 guarantee the rights embodied therein. 118. Pursuant to Article 2 of the Convention, such adaptation implies the adoption of measures following two main guidelines, to wit: i) the annulment of laws and practices of any kind whatsoever that may imply the violation of the rights protected by the Convention, and ii) the passing of laws and the development of practices tending to achieve an effective observance of such guarantees.144 It is necessary to reaffirm that the duty stated in i) is only complied when such reform is effectively made.145 119. Amnesty laws with the characteristics as those described above (supra para. 116) leave victims defenseless and perpetuate impunity for crimes against humanity. Therefore, they are overtly incompatible with the wording and the spirit of the American Convention, and undoubtedly affect rights embodied in such Convention. This constitutes in and of itself a violation of the Convention and generates international liability for the State.146 Consequently, given its nature, Decree Law No. 2.191 does not have any legal effects and cannot remain as an obstacle for the investigation of the facts inherent to the instant case, or for the identification and punishment of those responsible therefor. Neither can it have a like or similar impact regarding other cases of violations of rights protected by the American Convention which occurred in Chile.147 120. On the other hand, even though the Court notes that Decree Law No. 2.191 basically grants a self-amnesty, since it was issued by the military regime to avoid judicial prosecution of its own crimes, it points out that a State violates the American Convention when issuing provisions which do not conform to the obligations 143 Cf. Case of Garrido and Baigorria. Reparations (art. 63(1) of the American Convention on Human Rights). Judgment of August 27, 1998. Series C No. 39, para. 68; Case of Baena Ricardo et al. Judgment of February 2, 2001. Series C No. 72, para. 179. 144 Cf. Case of Ximenes-Lopes, supra note 14, para. 83; Case of Gómez-Palomino. Judgment of November 22, 2005. Series C No. 136, para. 91; and Case of the “Mapiripán Massacre”, supra note 137, para. 109. 145 Cf. Case of Raxcacó-Reyes. Judgment of September 15, 2005. Series C No. 133. para. 87; Case of the IndigenousYakye Axa Community, supra note 5, para. 100; and Case of Caesar. Judgment of March 11, 2005. Series C No. 123, paras. 91 and 93. 146 Cf. Case of Barrios Altos. Interpretation of the Judgment on the Merits. (art. 67 of the American Convention on Human Rights). Judgment of September 3, 2001. Series C No. 83, para. 18. 147 Cf. Case of Barrios Altos, supra note 140, para. 44.