We are increasingly living in a world of forever wars, wherein neither party has a foreseeable determinate pathway to victory. This chapter explores three challenges for traditional just war theory raised by forever wars. First, I discuss and reject the claim that forever wars necessarily fail the proportionality and reasonable prospect of success conditions of jus ad bellum. Second, although forever wars may not be disproportionate, they do suffer from compounding errors and indeterminacy in assessing likely future costs and benefits. Finally, I consider time-variant value and discounting, wherein future goods are deemed to possess less value than present goods. Discounting is a feature of the appraisal of financial and monetary goods, and it seems to play a role in some moral judgements also. Subjecting the expected costs and benefits of war to discounting over time significantly impacts the moral permissibility of forever wars. Time variability impacts ad bellum judgements about the justification of war as well as in bello decisions, generating a reason to prefer weapons that generate immediate strategic advantage, but whose collateral costs often occur far in the future.

This chapter expands on the concept of reciprocity, looking at how it can be defined, its key characteristics, and the three key functions it plays: in norm creation, as a condition, and in execution of the law. It examines the defining elements of reciprocity: proportionality, relativity, equality, and interdependence. The chapter goes on to examine the nature of reciprocity, and its relationship to custom and general principles, two sources of international law. It illustrates how it is reciprocity’s relationship with the structural characteristic of sovereign equality in international law that explains many of its roles and defining characteristics.

The chapter examines the relevance of (international) human rights law for international arbitration. It advances the proposition that (international) human rights law is part of the fabric of international arbitration. Hence the chapter sets out firstly the human rights norms and human rights methodology as far it is relevant in the international arbitration context. It then discusses human rights as the means to justify the existence of international arbitration. In its main part, the chapter considers the relevant human rights norms in commercial and investment arbitration and discusses the application of international human rights law in the commercial and investment arbitration context.

European Criminal Law in fact includes EU Law, influenced by European institutions and stemming from Member States agreements. At the same time, it is Council-of-Europe–inspired Law be it through minimum guarantees by the ECHR or through the European Court of Human Rights’ (ECtHR) influence on national criminal laws and procedures. Yet, one searches in vain for a European Criminal Code. Against the rumor that in consequence, European Criminal Law as such does not exist, the first chapter seeks to put up the umbrella and discuss and reveal sources and resources of current European Criminal Law and the intersections of EU Law on the one side and Council-of-Europe–inspired Law on the other side. That will in the end offer a panoramic view constituting European Criminal Law as the sum of European Union law imposing sanctions applicable in all Member States together with (Europeanised) national criminal law influenced by European law and Council-of-Europe inspired and set against European institutions and instruments that aim at ensuring effective criminal prosecution.

Chapter 5 examines how considerations of coherence manifest in the use of analogical reasoning by investor-state tribunals. In particular, it demonstrates through concrete examples and case studies that the persuasiveness and correctness of an arbitral award based on analogical reasoning depends on the degree of its internal coherence. It is argued that coherence in an analogical inference manifests in two ways. Firstly, in a methodological sense, coherence manifests itself in the way the adjudicator frames the legal question at issue and in the degree to which the analogy, as drawn, satisfies the elements of similarity, structural parallels, and purposiveness. Secondly, in a substantive sense, coherence manifests itself in the normative contextualisation of the legal question and in the moral appeal of the proposed interpretation derived from the analogy.

This chapter discusses the interpretation and application of the complex notions of necessity and proportionality, a cornerstone for any human rights adjudication and rights balancing exercise. Through an original and comprehensive analysis of the practice of the human rights bodies, this chapter shows the reader how these bodies managed to reach convergence on the interpretation and application of necessity and proportionality, despite all the impending factors.

In this chapter, the ethics and international law scholar Silja Voeneky and the mathematician Thorsten Schmidt propose a new adaptive regulation scheme for AI-driven products and services. To this end, the authors examine different regulatory regimes, including the European Medical Devices Regulation (MDR), and the proposed AI Act by the European Commission and analyse the advantages and drawbacks. They conclude that regulatory approaches in general and with regard to AI driven high risk products and services have structural and specific deficits. Hence, a new regulatory approach is suggested by the authors, which avoids these shortcomings. At its core, the proposed adaptive regulation requires that private actors, as companies developing and selling high risk AI driven products and services, pay a proportionate amount of money as a financial guarantee into a fund before the product or service enters the market. The authors lay down what amount of regulatory capital can be seen as proportionate and the accompanying rules and norms to implement adaptive regulation.

This chapter makes the case for judicial morality as a safeguard against result-selective reasoning, a decision-making flaw especially pernicious in human rights adjudication. Human rights claims are more value-laden than other judicial work. They can tempt judges to depart from disciplined judging according to the rule of law. One purpose of the rule of law is to constrain discretionary judicial power. Research into the psychology of judging supports the need for constraints. But the legal system affords opportunities – margins of judicial manoeuvre – to engage in result-selective reasoning, from the indeterminacy of human rights texts, the replacement of rules with standards, and the adoption of proportionality analysis. The rule of law’s constraints are not self-enforcing and cannot safeguard against the failure of judges to abide by them. What is required is commitment to judicial morality comprising the modes of judicial responsibility: do no harm, and then, do the right thing, for the right reason, in the right way, at the right time, and in the right words. When judges neglect these moral imperatives, they undermine the quest for consistent adjudication that underpins justice.

Proportionality purports to contrast means with ends to decide whether a specific rule breaches the Constitution. The chapter starts by analyzing discussion of the 2016 agreements between the Colombian government and the FARC guerrilla in the Colombian Constitutional Court, whose justices split over the standard of review to be used to decide the scope of the special legislative powers conferred to the president to implement the Peace Agreement. Part of the Court believed that those special presidential powers were to be scrutinized under stringent standards similar to those applied in judicial review of emergency powers. Others pointed out, by contrast, that those powers were to be deployed not in an emergency setting, but in a transitional one where more lenient standards of review apply. The chapter suggests that this debate between exception and transition illuminates the analysis of how judicial discourses build relations between means – legislative and executive norms – and goals – attaining peace – adding dimensions to the proportionality/necessity framework as a field where judges deploy their powers to exert political control over other public branches. While the Court framed the debate around the concept of “necessity,” Colombian constitutional discussions suggest that necessity and proportionality could even be interchangeable concepts.

Proportionality has been a recurrent method of adjudication in the Inter-American Human Rights System in different types of cases – mainly, in cases of limitations of human rights and in cases of equality and nondiscrimination. This chapter focuses on the use of proportionality by the Inter-American Court in the second group of cases. First, the chapter addresses the complexity of equality and nondiscrimination positive provisions, with specific emphasis on the formulas employed by the American Convention on Human Rights. Second, it discusses the type of cases in which proportionality is useful and serves its purpose of narrowing discretion in the adjudication of equality and nondiscrimination provisions, which are those involving direct discrimination. It also presents reasons to be skeptical about the usefulness and appropriateness of proportionality in the adjudication of other types of cases, specifically those dealing with covert and indirect discrimination. The analysis also discusses the potential use of proportionality in other cases related to the substantive dimension of equality and nondiscrimination.

This chapter explores the different levels at which proportionality intersects with and shapes criminal law. Proportionality has been always important in the field but its impact increases if we approach the frontiers of penal intervention from the principles that inform an equalitarian understanding of the law – a central project in contemporary Latin America. The chapter shows the relevance how judgments of excess or defect based on proportionality shape the contours of criminal policy, criminal doctrine and the theory of criminal responsibility, criminal procedure and criminal punishment While exploring these different levels with Latin American social and political backgrounds in mind, and bringing inter-American doctrine into the analysis, the chapter also invites future, broader analysis about how the uses of proportionality in the domains of criminal and human rights law can illuminate and complement each other.

The proportionality exam as developed by the German Constitutional Court expresses the idea that constitutional rights cannot be overruled neither by other constitutional rights nor public interests. Instead, colliding rights and public interests should be satisfied as factually and legally possible. The chapter defends that the integrated proportionality test, which analyzes suitability, necessity and proportionality in its narrow sense, while including a modulation of the intensity of the scrutiny, may become a powerful adjudication device. It allows for a nuanced implementation of the three subprinciples of the proportionality exam, enabling courts to level the ground for disadvantaged groups. To show the usefulness of the modulated exam in dealing with structural inequality in Latin America, two cases involving political rights decided by the Inter-American Court of Human Rights (Castañeda Gutman and Yatama v. Nicaragua) are examined.

This chapter aims to analyze one aspect of the proportionality test in the case law of the Brazilian Supreme Court: its use as a tool for deciding cases involving socioeconomic rights. If these rights are one of the core elements of a transformative constitution, using the proportionality test to decide these cases raises the question of its transformative potential. We argue that there are several reasons for concluding that proportionality does not play a transformative role in Brazil. Some of these reasons are related to the general debate on the transformative potential of litigation; others are related to how the Brazilian Supreme Court uses the proportionality test, which could be summarized as follows: First, the Court has often used the proportionality test as a rhetorical device only; second, due to peculiarities of the decision-making process of the Court, proportionality has never been employed by the majority of its judges; third, in the realm of socioeconomic rights, the role of proportionality has been frequently undermined by other types of reasoning.

The chapter discusses distributional analysis as a method of legal analysis interested in understanding the consequences of rules. While recognizing that this method shares this goal with proportionality analysis, the author intimately discards a reconciliation of both based on their different relationship to a theory of democracy. The author argues that proportionality analysis is wed to a vision of judges as restrained by the commands of legislators (or constitutional lawmakers), while distributional analysis sees judges as political actors entrusted with realizing the goal of redistribution. The case of gender mainstreaming is used to illustrate that arguing in favor of the use of distributional analysis does not mean forcing judges into continually adopting structural injunctions, nor provokes such levels of polarization that the sought-after redistribution is sabotaged by increased levels of countermobilization or backlash.

The Colombian Constitutional Court has decisively undertaken the role of guaranteeing the normative force of economic and social rights. It has devised several tools to that effect, among them a test to evaluate regressive measures. This chapter examines rulings that review statutory norms in the abstract, before arguments that denounce them as illegitimate retrogressions in the enjoyment of social and economic rights. These claims are assessed by applying what we call the “integrated regression test.” The chapter establishes the meaning, structure, operation and efficacy of this test, which uses proportionality analysis as an allocation method. It dissects how it operates to safeguard rights when their minimum core or preexisting associated benefits are withdrawn. The integrated regression test proves to be a strong and complex scrutiny, even if not completely unified in its use, with a wide range of singularities and a tendency to be more protective of social rather than economic rights.

This chapter explores the contrasting role of proportionality discourse in the USA and in Latin America. Although the USA provided an important constitutional model for Latin American countries, the latter does not share the former’s disinterest in the proportionality framework, which is considered foreign to the legal tradition of the country despite the fact it is arguably harmonic with the approach to law creation in the common law tradition. The chapter seeks possible explanations for the contrast in four elements: the importance in Latin America of centralized, specialized constitutional jurisdiction; the tradition of borrowing constitutional jurisprudence from abroad; the openness to constitutional change and innovation; and sensitivity to the egalitarian potential of rights review, even if that potential remains largely unrealized, which favors experimentation around proportionality. The USA sits at the opposite end of the spectrum along each of the dimensions that support proportionality analysis.

This chapter presents an overview of the use of proportionality in the case law of the Mexican Supreme Court, which has used it mainly to analyze human rights restrictions established by the legislator in statutes. The study identifies two periods. In the first period, the Court begins to use proportionality to analyze the constitutionality of legislative classifications that allegedly violated the right to equality, under a syncretic methodology that is applied not always consistently. More recently, the test has been used more often and regarding rights of very different types, providing a crucial support to the enforcement of the 2011 human rights’ constitutional amendments. The chapter documents the reception of proportionality in terms of both substance and methodology but also offers insight on the main difficulties experienced along the process and on the challenges its use in the Mexican judiciary poses for the future.

The ECB started its QE called the PSPP in 2015 as a new monetary policy measure. By purchasing vast monthly amounts of main Member State government bonds, the ECB aimed to force investors towards riskier assets, which in turn, was to increase asset prices and support bank lending, and ultimately lead to growth and inflation. Constitutionally, QE was a new type of complication for the European Macroeconomic Constitution. The ECB became the largest creditor of Member States it was prohibited to finance. The constitutional assessment of the PSPP combines the analysis of the CJEU’s Weiss case that contains very limited constraints for the ECB, and more economic-constitutional and thus substantive analysis. One key question is whether the PSPP is monetary policy, which can be analysed through its objectives, its economic content and examples of other central banks that mostly support an affirmative conclusion. The euro area constitutional structure adds further complications that were also raised in the FCC’s Weiss judgment. The PSPP has arguably broader implications for other areas of economic policy, as it facilitates Member States public finances and increases wealth differences by increasing asset prices, as well as making the ECB deeply dependent on Member States public finances.