Under the rule of lex posterior derogat lege anterior, a later rule is presumed to trump an earlier rule.
Similar limitations exist for the lex posterior rule.
Article 311.1 of the 1982 UN Convention on the Law of the Seas (UNCLOS) (64) confirms the lex posterior principle when stating that "[t]his Convention shall prevail, as between States Parties, over the Geneva Conventions on the Law of the Sea of 29 April 1958." In these cases, it is possible to assume a fictitious WTO or UN law of the sea "legislator." Granted, the actual negotiating parties change constantly--countries join and leave treaties as the United States did with UNESCO, withdrawing in 1984 and rejoining in 2003, (65) or China, which left the GATT in 1950 and joined the WTO in 2001.
A broader application of the intra-systemic lex posterior rule is found in Article 30 paragraph 3 of the Vienna Convention: for parties bound by two treaties, "the earlier treaty applies only to the extent that its provisions are compatible with those of the later treaty." Interestingly, the very title as well as paragraph 1 of Article 30 state explicitly that this lex posterior rule applies only between "treaties relating to the same subject matter." This suggests that the rule was written mainly with intra-systemic conflicts in mind, that is, successive treaties, within the same field or branch of international law, broadly speaking.
"[T]he relationship between lex specialis and other norms of interpretation [e.g., lex posterior derogat legi priori] or conflict solution cannot be determined in a general way...
Thus, the maxim of lex posterior must be considered when evaluating the IHL-IHRL relationship.
In addition, the maxim of lex posterior would further support the application of IHRL, as most IHRL rules are post IHL--at least Common Article 3, if not the Second Additional Protocol.
La Corte Suprema argentina mantuvo este criterio hasta 1963, cuando comenzo a aplicar la antigua regla interpretativa, lex posterior
derogat priorem, colocando en pie de igualdad las leyes y los tratados y haciendo prevalecer la norma posterior sobre la anterior.