The emergence of new concepts such as JUS COGENS and Obligations erga omnes imply fundamental change in the nature of international law. The revision of the traditional system of international law and make substantive hierarchy and weaken the foundations of the theory of the collapse of the international community of the direct consequences of the emergence -of these universal and binding obligations. the public acceptance and doctrine, limiting government with the rules of JUS COGENS and fading belief in the binding element of the consent of governments, the international community and humanitarian assistance to the institutionalization of more comprehensive rules, strengthen the monitoring of international institutions and criminal and civil executive guarantees and the impact of the emergence of these new concepts in international law are. We can say that JUS COGENS Not only has prevented the anarchy of the international community but also means strengthening structural framework of the international community and to provide further convergence.

The peremptory norms in any legal system lead to the formation of a hierarchy among norms and their regulation. Until recent decades, international law had not formally recognized this fundamental concept. However, there have been few references to this concept in case law, legal teachings, and doctrines. The existence of peremptory norms (JUS COGENS) in international law requires its acceptance and recognition by States. Therefore, the practice of states in this regard is of particular importance. Certain states, such as France, have never agreed with such a concept, and others, Iran, for instance, despite the general acceptance of the concept in international instruments and studies, expressed their own special views on the compulsory dispute settlement procedures as to JUS COGENS and suggesting a list of examples of JUS COGENS. The examination of Iran's approach to the identification of the concept of the JUS COGENS and related issues, particularly in the recent study of the International Law Commission on the JUS COGENS, is the subject of this article. Practice of Iran in this regard, demonstrates its adherence to the values of the international community and ways of interacting with it.

International law is produce of sovereignties and in a real sense, of agreements among states. But it has nowadays been asserted humanity and laws and rights belong it, has reached to a level that we can say of humanity of international law. In other words, it has been spread in every areas of international law such as international humanitarian law, international criminal law, diplomatic and consular law, international environmental law and etc. Therefore, the possibility of conflict between norms and rules of international law is visible in some legal regimes and branches of it and in a wider scope in international legal order. In this regard, what is controversial in contemporary era of enforcement of international law is conflict and contrast between state immunity and JUS COGENS norms. This would be seen a discussion between value and reality. Hence, the paper will seek on this point and also contemporary transformations regarding these norms.

International Law has it's Constituent elements (legal systems, regimes and collections of rules); Those have interrelations from which legal networks are created. Having this in mind, the question is whether these Constituent elements only have horizental nexus or are ordered by means of factors which unified them in a vertical manner and because of that International Law is named legal order. So if such a factor(s) does exist, hierarchy of norms in International law will come to in exist and so on normative hierarchy of International Law could be deemed. Among different modes of hierarchies (structural, substantial, logical and axiological ), this article is focused on substantial factor of Hierarchy of norms in International law which is best crystallized in International law in concept of JUS COGENS. Among many questions of JUS COGENS, (Source of JUS COGENS Obligations, The Role of Consent in the Creation and Modification of JUS COGENS Norms, Scope of Concept of JUS COGENS, Function and Effects of the JUS COGENS), in this study Concentration will be on the theoretical foundations of JUS COGENS which shed light on all disscusions of the conceptual and practical aspects' of JUS COGENS to contribute to formulate a map of the doctorine of JUS COGENS.

nternational law, as a scientific trend, has various components (systems, regimes and (sets) of legal rules) that are united by the status or factors so as to become a system. One of the concepts claimed to act as unifying factor in the constituents of international law, making hierarchy and order is the concept of the JUS COGENS. However, there are controversies in different conceptual and scientific dimensions of JUS COGENS. After the formation of JUS COGENS, various views on the concept and definition of it in the field of international law have been emerged. These views can be categorized in two forms of classical and modern understanding of the principle. The view of this study is that the distinct teachings of the highly scholars of international law on the concept of JUS COGENS suggest that the one-dimensional perspective on JUS COGENS cannot be a reflection of the fluid and dynamic role of this principle in the modern international legal order. Therefore, nowadays, due to the complexity of international law, JUS COGENS must inevitably emerge in distinct legal forms and techniques, in order to be able to maintain its system-making feature.

The concept of JUS COGENS entered into international law through the law of treaties and today has become one of the most important and effective rules of international law. The principal and recognized function of the JUS COGENS is to invalidate any treaty which is in conflict with it. Some States resort to unilateral acts to achieve their goals and to avoid the limitations imposed by the JUS COGENS, because given the lacuna in international law, they consider those acts to be outside the influence of the JUS COGENS. In recent years, we have seen the functional development of the JUS COGENS in areas other than the law of treaties. This article, examines the function of JUS COGENS in the field of unilateral acts of States, to determine if unilateral acts of States, where they conflict with a peremptory norm, produce any legal consequences, and if the JUS COGENS has any impact on such acts, is its function in the field of unilateral acts similar to that of the law of treaties or does it has a different function.

Undoubtedly, JUS COGENS or preemptory norm is always recognized as the highest source of international law. Nevertheless, the judicial review of International Court of JUStice caused doubt in the absolute priority of JUS COGENS when violation of JUS COGENS and immunity are simultaneously argued in a case. Especially, in the cases concerning the Arrest Warrant (Congo v. Belgium 2002) and the Jurisdictional Immunities (Germany v. Italy 2012), ICJ tried to separate procedural and substantive norms and declared that the norms of immunity and JUS COGENS are different in nature, thus they couldn’t oppose each other but immunity as a procedural norm could prevent deciding about merits. In this article, by using descriptive – analytic method, the rationale behind the decision of ICJ is analyzed in order to know that if immunity is considered procedural and JUS COGENS is recognized as substantive norm in international law and how these norms interact. Evaluation of doctrine shows that there is no certainty about the quality of the separation of procedural and substantive norms and their proof in international law. Therefore, the court’s decision in choosing the approach could cause an insecurity in the peremptory place of JUS COGENS.

This article contributes to the ongoing scholarly debate on the possible effect of JUS COGENS norms. For the purpose of the article, it is assumed that peremptory norms certainly exist in positive international law. According to the argument, even if we limit the effects of JUS COGENS norms to those described in the 1969 Vienna Convention, the JUS COGENS concept takes us farther than most commentators seem to realize. This is due partly to the power potential invested in the JUS COGENS concept, and partly to the intricate structure typical of legal norms. In fact, as argued in this article, if we take the existence of peremptory international law to its logical consequence, it will carry too far: most actors in the international arena will consider the effects unacceptable. Using as an example the JUS COGENS norm most often referred to in the literature –the principle of non-use of force– it is a purpose of the present article to establish this proposition as valid. A second purpose is to attract attention to what appears to be the really crucial question for further discussion: How should the effects of JUS COGENS be limited? Whoever opened the Pandora’s Box that once contained the JUS COGENS concept obviously did not fully realize the consequences that this would have for international law in general. How can this situation be remedied?

One of the most significant sources of Public International Law is the Peremptory Norms (JUS COGENS),According to Article 53 of the 1969 Vienna Convention: "the Peremptory Norm of General International Law is 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. " Nowadays, the Famous viewpoints of lawyers are that: Fundamental Human Rights became part of the Peremptory Norms of International Law (JUS COGENS). According to article 4, paragraph 2 of International Covenant on Civil and Political Rights, 1966 (ICCPR), Fundamental Human Rights are those rights, under any circumstances, States cannot violate or restrict them. This article explains the characteristics of both categories (Peremptory Norms of International Law and Fundamental Human Rights Norms) and makes it clear that the Peremptory Norms of International Law are changeable and can be modified by a subsequent norm of General International Law having the same character, contrary to the fundamental human rights. Therefore, the relation between these two categories of norms is kind of "Generality and peculiarity in some respect" Considering the characteristics of both of them, modifying the Fundamental Human Rights into Peremptory Norms are incompatible with the nature and essence of Fundamental Human Rights. Therefore, instead of putting Fundamental Human Rights in the position of Peremptory Norms, it would be better if they were seen as their immutability position.