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.

The Introduction gives a snapshot of the current status of capital punishment around the globe. It gives current statistics from Amnesty International and describes Amnesty International's anti-death penalty campaign in the 1970s that led to the Declaration of Stockholm, which expressed "total and unconditional opposition to the death penalty." The Introduction describes the divide between retentionist and abolitionist countries, highlighting countries that have outlawed capital punishment in their constitutions or through judicial rulings. After detailing how the death penalty was traditionally seen as something other than torture, the Introduction discusses the law's evolving nature--and how the death penalty is increasingly seen as a torturous and cruel punishment that violates human dignity and fundamental human rights. Noting that death sentences are no longer treated as a "lawful sanction" in many locales, the Introduction describes how the U.N. General Assembly has voted on multiple occasions for a global moratorium on executions. The Introduction summarizes the current state of international law as regards capital punishment and previews the book's content.

As a doctrine of positive international law, jus cogens superveniens gives juridical effect to the natural law’s prohibition of conduct violative of aspects of the transnational common good that reflect absolute human rights. In order to be fully valid in the sense that it commands a moral obligation of compliance, a measure for regulating the life of a community must be reasonable. A measure cannot be reasonable if its purpose is not the preservation or enhancement of the common good. The common good is the full array of physical, cultural, and institutional arrangements that facilitate the ability of persons in their various communities, including the transnational community, to advance their human flourishing. Human rights are conclusions of practical reason that always constitute essential aspects of the common good. Some human rights are ‘absolute’ in that they are not subject to limitation or restriction on any grounds, because any such limitation or restriction can do nothing but damage the common good. Although natural law is binding in reason, the positive law and other juridical measures of official authority are frequently required to effectively serve the common good.

This chapter discusses how customary international law enters the sphere of EU law and to what extent it determines the relationship between the EU institutions, its member states and individual persons. Against this background, it is examined how customary international law is integrated into the EU legal order, what status it enjoys within that legal order, how it can be applied by EU institutions and whether it can serve as a benchmark for judicial review. Assuming that EU law is an autonomous domestic legal system, these questions are discussed from the perspective of EU constitutional law. Here it is argued that the Court of Justice of the European Union, in evaluating these issues, focusses too much on the idea of the autonomy of EU law. In order to provide provisions of customary international law with practical effect the validity of EU law must also be able to be reviewed on the basis of international law standards.