This title examines the concept of normative pluralism in international human rights law, focusing on the coexistence and interaction of multiple legal systems and norms within the global human rights framework. It explores the treaty-based structure of human rights norms, including various international and regional human rights treaties, and discusses the role of customary international law, general principles of law, and jus cogens in shaping human rights obligations. The section also addresses the impact of nonconventional sources of human rights law, such as judicial decisions and soft law instruments, on the development and enforcement of human rights standards. By analyzing the complexities of normative pluralism, this title highlights the dynamic and evolving nature of international human rights law and the challenges in achieving coherence and consistency across different legal systems and cultures. It also emphasizes the importance of dialogue and cooperation among international, regional, and national actors in promoting and protecting human rights globally.

The distinct prohibitions of torture and other forms of ill-treatment have crystallized as customary international law as the chapter discusses. In the specific case of torture, its prohibition is also a peremptory (jus cogens) norm of international law – a rule that is applicable in all circumstances and in any place. The chapter also discusses the geographical, material, personal, and temporal jurisdiction of the prohibitions of torture and other ill-treatment under international law more generally.

Genocide is sometimes called the ’crime of crimes’. The word was coined by Raphael Lemkin in 1944, then declared an international crime by the United Nations General Assembly. In 1948, the Genocide Convention was adopted. As the first human rights treaty of modern times, it constituted a significant intrusion into what had previously been a matter exclusively of domestic concern. This explains the narrow definition of the crime of genocide. It requires proof of an intent to destroy a national, ethnic, racial or religious group. Only a half century after its adoption did the Genocide Convention take on real significance with inter-State cases being filed at the International Court of Justice and many prosecutions at the International Criminal Tribunals for the former Yugoslavia and Rwanda. The Convention requires that States Parties punish genocide but they are also required to prevent it, even when it takes place outside their own territory. More than 150 States have ratified the Genocide Convention. Genocide is also prohibited under customary international law. It is generally agreed that the duty to punish genocide is a peremptory norm of international law (jus cogens).

This chapter addresses the suggestion that for a special regime to exist, community members must have a shared repertoire. In the context of international law, to claim that a group of international law specialists have a shared repertoire is to assert that they consider the use of certain rhetorical tools appropriate. As Chapter 5 argues, the existence of such a presupposition can be inferred from, amongst others, the use by specialists of distinct concepts, a distinct terminology, a distinct method, and distinct theories.

This chapter examines the relationship between the prohibition of the use of force in article 2(4) of the UN Charter and customary international law: if they are identical, the role the customary rule plays in the interpretation of article 2(4) and which one to interpret or apply to determine the meaning of a prohibited ‘use of force’. In doing so it examines the following concepts: the use of pre-existing or subsequently developing custom to fill gaps in the treaty, the use of subsequently developing custom to informally modify the interpretation of the treaty, an evolutive interpretation of the UN Charter and informal treaty modification through subsequent practice. It argues that since article 2(4) is the origin of the customary prohibition, it is not appropriate to use pre-existing or subsequently developing customary international law to fill gaps in interpretation of article 2(4) nor to use subsequently developing custom to modify article 2(4). It concludes that due to the present relationship between the customary and Charter prohibitions, the preferable approach to determine the meaning of prohibited force under international law is to focus on interpreting the UN Charter.

International human rights law is part of public international law and shares a number of its features, including sources, obligations (primary rules) and state responsibility (secondary rules). While international human rights law has formed within the broader setting of international law, it has developed distinctive features. Traditional international law was an order based on the sovereign interests of states as its sole subjects. In contrast, international human rights law is characterised by its emphasis on common interests that reflect the fundamental values of the international legal order. This value-based approach is evident in the concept of jus cogens, or peremptory norm, and the notion of erga omnes, obligations owed to the international community as a whole. Undoubtedly, international human rights law can form an important component of a new international order or international constitutionalism. However, unilateralism, selectivity and fragmentation, in addition to challenges of effective implementation, are restraining factors that may slow down, if not undermine, ‘constitutional’ developments at the international level. This chapter examines these dynamics and discusses the key building blocks of international (human rights) law: its sources; its rights and obligations and the scope of their application; and its implementation as well as state responsibility and enforcement.

This chapter examines the process whereby the concept of jus cogens was introduced into international law during the 1968–69 Vienna Conference on the Law of Treaties. The 1969 Vienna Convention on the Law of Treaties, the conference’s final product, declared that some rules of international law command universal authority, with Article 53 recognizing ‘peremptory norms of general international law’ (without specifying which norms counted as such). Yet the negotiations through which jus cogens entered into the law of treaties were marked by wide-ranging debates about the nature and limits of the treaty-making power, and ultimately about the basic structure and orientation of international law more generally. On the one hand were lawyers and diplomats from socialist and nonaligned states for whom the concept was potentially useful as a means of undercutting the legality of unequal treaties, colonial concession agreements, and other substantively unjust instruments. On the other hand were lawyers and diplomats from industrialized countries who were committed to the traditional principle of pacta sunt servanda—the ‘sanctity of compacts’—and deeply skeptical of any attempt to introduce a normative spectrum in which a select group of rules would have controlling authority over all others.

The author argues that ‘will’ and ‘consent’ are different. According to him, no State’s will is entirely free. However, this does not preclude its consent from being valid. State consent displays different shades of will: while unilateral acts are the epitome of ‘willing consent’, the degree of willingness required when accepting a treaty is weaker, until it almost disappears in the case of custom, or general principles of law. The author argues that opinio iuris and consent are also different notions: you may feel legally bound even if consent is very remote. However, whatever role ‘will’ plays in the formation of rules, once the rules exist, States are, according to the author, bound and their will is trapped. The author makes the argument that, if neither will nor consent explain the basis of a State’s obligation when it is no longer willing to implement it, they nonetheless have a stabilizing and legitimizing role. He argues that consent makes the acceptability of the obligation stronger, by comforting its legitimacy, which also makes its implementation more effective.

Chapter 1 provides an exposition of the general breadth and scope of the contemporary prohibition of the threat or use of force. After setting the prohibition in its historical context, it then examines the sources of the prohibition and its status as a ‘peremptory’ or ‘jus cogens’ norm of international law and what this means in terms of the prospects for its adaptation and modification in the future. While much focus has been traditionally placed upon the use of force, by comparison relatively little attention has been given to the threat of force, despite both coming under the contemporary rule against force. As such, the chapter sets out and provides an examination of the concept of a threat of force. While the prohibition is of undoubted importance, the decentralised nature of the international legal system means that accountability and responsibility for its violation are uncertain. The chapter seeks to examine this issue in detail, while also providing attention to the ‘human element’ to the prohibition, as well as assessing the continued relevance and effectiveness of the norm.

The starting point for discussion and analysis of the sources of international law is almost invariably art 38 of the Statute of the International Court of Justice (‘ICJ Statute’), the International Court of Justice being the primary judicial organ of the United Nations. Article 38 lists the sources of international law as comprising treaties, custom, general principles of law, and – as subsidiary means for determining the law – judicial decisions and academic writing. However, in the 75 years since the adoption of the ICJ Statute, newer sources of legal obligation have emerged for the international community. These often involve non-state and intergovernmental actors in their creation. This chapter explores both the traditional and newer sources of international law and assesses how they are adopted and created.

Although the Vienna Convention on the Law of Treaties devotes nine articles to invalidity of treaties, cases rarely arise in practice. Circumstances covered by the Convention include violation of internal law, error, fraud, corruption, coercion and violation of a peremptory norm of international law (jus cogens). Article 46 of the Convention covers the first of these, providing that a state may not invoke the fact that its consent to be bound has been expressed in violation of its internal law unless that violation was manifest and concerned a rule of fundamental importance. The chapter examines the meaning of the key terms of this provision and possible cases in which this might arise. In the context of coercion, the chapter looks at treaties which might be concluded by the threat or use of force, peace treaties and unequal treaties. The scope of peremptory norms (jus cogens) is also discussed, together with the consequences of invalidity.

The chapter deals with the role of the ICJ in the development of international law from both a doctrinal and a practical perspective. It considers concrete examples of the way in which the Court’s judgments and opinions have had an influence on the development of international law, and it concludes that the Court has in practice had a significant impact on the development of international law, even though that goes beyond its core mandate.

The chapter traces the origins of human dignity, showing how it was originally used to denote titles of honor but is now seen as a universal human right or as undergirding universal human rights. In the context of discussing dignity rights, the chapter highlights international human rights treaties and national constitutions making refeerence to the concept of human dignity, which, in modern usage, has to do with the inherent worth of a life. The chapter discusses how human dignity is the foundation for many human rights, including the right to life, the right to be free from torture and other forms of cruelty, and the right to be free of discrimination. The chapter describes existing jus cogens norms prohibiting various acts that violate fundamental human rights, concluding that the death penalty must be abolished because it makes use of credible death threats, inflicts psychological torture, and violates an array of basic human rights. The chapter details how non-lethal corporal punmishments have already been abandoned and how the death penalty has been abolished or curtailed in many countries, with international criminal law tribunals precluding the death penalty's use.