The primacy of human rights as a core objective of the United Nations is encapsulated explicitly in article 103 of the UN Charter: "In the event of a conflict between the obligations of the Members of the United Nations under the present Charter and their obligations under any other international agreement, their obligations under the present Charter shall prevail.” When any treaty is interpreted according to its "object and purpose” in line with article 31(1) of the Vienna Convention on the Law of Treaties (1969), that object and purpose must cohere with, or at least not offend the purpose and principles embodied in the UN Charter that article 103 seeks to protect. Even when an international court is not called upon to interpret a treaty, it is still required to observe the coherence of the international legal system given both the peremptory norm status of article 103 and the broad reading of that article’s reference to international agreements.
Although jurists and UN bodies have tried to classify certain rules, including rights and duties, with adjectives such as "inalienable, "inherent” or "fundamental,” these terms have not assumed precise legal meaning, but have influenced some tribunals’ interpretation of human rights and corresponding duties, including treaty obligations. Some eminent court opinions have supported the view that certain over-riding principles of international law form the body of jus cogens, or obligations of behavior that states owe to the entire international community as a whole. A principle of jus cogens is also considered a preemptory norm in international law. The ICJ has ruled that "such obligations derive, for example, in contemporary international law, from the outlawing of acts of aggression, and of genocide, as also from the principles and rules concerning the basic rights of the human person, including protection from slavery and racial discrimination.” Such rules cannot be diluted or superseded by an international treaty, but only by the codification of, or other means of establishing another countervailing norm. The UN Charter principles of nondiscrimination and self-determination, as well as crimes against humanity, fall into the category of jus cogens. As the International Law Commission accepted and the Vienna Convention on the Law of Treaties (1969) affirms that "A treaty is void if, at the time of its conclusion, it conflicts with a peremptory norm of general international law.”
The least that can be said is that public international law has an effect on private international law and the relationship between the two disciplines involved public international law significantly governing private international law.
 U.N. Charter art. 103
 113. U.N. Charter art. 103; see also Vienna Convention on the Law of Treaties on relations between States and International Organizations, or between/among International Organizations art. 30 ¶ 6, 21 March 1986, 25 I.L.M. 562 ("The preceding paragraphs are without prejudice to the fact that, in the event of a conflict between obligations under the Charter of the United Nations and obligations under a treaty, the obligations under the Charter shall prevail.”).
 Stanislaw E. Nahlik, "Book Note, 84 AM. J. INT’L L. 779 (1990) (reviewing Lauri Hannikainen, Preemptory Norms (jus cogens) in International Law: Historical Development, Criteria, Present Status ).
 The Vienna Convention defines a peremptory norm of general international law as "a norm accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character.” The Vienna Convention on the Law of Treaties, Article 53: Treaties conflicting with a peremptory norm of general international law (jus cogens).
 Barcelona Traction (second phase). ICJ Reports (1970), 3 at. 32.
 Also the acquisition of territory by force and piracy. See Ian Brownlie, Principles of Public International Law (Oxford: Clarendon, 1991), pp. 512–14.
 In the ILC’s terms, "a treaty is void is it conflicts with a peremptory norm of general international law from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character.” Final draft on the law of treaties (1966), Article 50. See Yearbook of the International Law Commission (1966), ii, pp. 247–49.
 Vienna Convention, op cit., Article 53.
 Dan Jerker B. Svantesson, "The Relation between Public International Law and Private International Law in the Internet Context,” Yearbook of New Zealand Jurisprudence, Volume 9 (2006), pp. 154–60.
 "Discussion of the relationship of private to public international law is meaningful, however, only if private international law is carefully delimited.” John R. Stevenson, The Relationship between Private International Law and Public International Law, Columbia Law Review, Vol. 52, No. 5 (May 1952), pp. 561–88