The introduction offers a historical overview of terrorism through the ages and describes the development of international counterterrorism law. It discusses the interplay between terrorism and international crimes such as genocide and crimes against humanity. It also introduces some of the controversy surrounding terrorism as a term.

This Introduction begins by outlining what is meant by international relations. It then tells the story of how and why the academic study of international relations emerged in the early twentieth century before considering the need to ‘globalise’ the study of international relations – to make it an academic discipline more open to non-Western perspectives. It sketches the changing agenda of international relations, a shift that some scholars describe as a transition from international relations to world politics or from the ‘traditional’ to the ‘new’ agenda. Although there is little doubt that, as political reality has changed, new theoretical tools have become necessary to grasp it, we should not assume that the myriad changes in our world have rendered the ‘traditional’ agenda obsolete. As we shall see, the ‘new’ agenda supplements, but does not supplant, the ‘traditional’ agenda. It is now more important than ever to consider the relationships between ‘traditional’ and ‘new’ agendas, and to globalise IR.

This chapter provides a brief introduction to the ethics and laws of war. The first part outlines what international law and the ‘just war’ tradition say about war; the second explores the conduct of war; and the third examines two recent dilemmas as examples of moral and legal debate: the legitimacy of pre-emptive self-defence and the use of cluster bombs.

This chapter introduces the concept and practice of security in international relations. It explores the dilemmas faced by states, individuals and the global community by first looking at contemporary crises and disagreements about security; second, examining how security has been differently defined and focused; and third, surveying how different theoretical approaches have understood and analysed security.

Liberalism is at the heart of modern ‘Western’ history, politics, and international relations. Central to understandings of liberty, freedom, democracy, rights and the rule of law, liberalism has animated debates on abolition and empire, war and peace. This chapter provides an account of liberalism as a contested phenomena that originated at least in the eighteenth century and has had profound international political consequences ever since. To tell this story, the chapter begins by considering how to make sense of the contestations surrounding liberalism, before examining how and why liberalism matters to International Relations at key moments of its development as a discipline: in the age of empires, the inter-war years, during the Cold War and ‘new’ world which ensued, and now in this epoch of endless war.

The debate about whether state or non-state players have primacy has been a major preoccupation for International Relations researchers. This chapter argues the key is not so much to determine which players are dominant, but how they interact to produce the prevailing order. The 1985 book Bringing the State Back In declared the return of the state for international politics and political economy (Evans et al. 1985). This chapter argues instead for bringing state–society relations ‘back in’ to the centre of what makes international relations.

International law governs almost every facet of international life, from the mundane to the complex. This chapter discusses the role of international law in world politics. It begins with a discussion of the content of international law, explaining the sources of law and how we identify them. It then addresses the question of why the study of international law is foundational to the study of international relations. The chapter offers two answers to this question. First, international law is important in the study of international relations because the nature and extent of its influence are among the core debates in international relations theory. Second, the study of international law is important because law is at the heart of many international disputes today. The chapter concludes by considering two examples of ‘law in action’: the legal decision regarding Chinese activities in the South China Sea and the contemporary debate over membership of the International Criminal Court.

This chapter explains the legal and political features of the United Nations. It begins with a short introduction to the UN Charter, which shows the framework of international law that defines, limits and empowers the organisation. It then puts these into a more practical setting, which emphasises how the United Nations is at the same time an actor, a forum and a resource for governments.

Processes of arms control and disarmament remain relevant in a world where armed conflict between states is still highly visible in international politics, and where civil wars and domestic conflicts claim hundreds of thousands of lives every year. Much attention is focused on the need to control and eliminate weapons of mass destruction (WMDs), especially nuclear weapons, given the hugely destructive nature of these armaments, but controlling so-called ‘conventional weapons’ – those not classed as WMDs – is also important. Conventional weapons, especially small arms and light weapons, are responsible for most of the casualties we see today, even as arms control efforts have only recently begun to focus on these.

Chapter Six looks at the role of international law in the Trump administration State Department. Former policymakers gave their opinion on the extent of the effect of the Trump administration on State Department policymaking and discussed potential long-term effects. The Trump administration generally displayed a negative view toward international law, institutions, and agreements, as evidenced by its words and in its actions, a view at odds with the prevailing State Department culture. More significantly, the Trump administration took unusual steps to stifle dissent within the State Department. Former officials expressed a range of perceptions regarding the Trump administration’s effect on the State Department. A minority believed that the administration’s views and actions significantly affected attitudes and practices within the Department regarding international law and institutions. The majority believed that effects on attitudes were more likely to be felt at the policy-decision level, rather than at the lower, policy development level. That is, attitudes among rank-and-file and career State Department officials probably remained unchanged and were likely to “bounce back” after the 2020 election. Nevertheless, a reprise of the Trump administration, or a similar administration, could ultimately affect not only practices at the State Department but attitudes among officials as well.

Chapter Three explores the views of former officials regarding compliance by states with international law. Almost all former officials believed that international law constrains state behavior, at least to some extent, and that states comply with international law much of the time. The top positive factors favoring compliance, as revealed by frequency counts, were reputational concerns; state interest in a stable legal and institutional system; reciprocity, or the prospect of retaliation; ethical considerations, including ethical values underlying international law rules and respect for the rule of law; idiosyncratic factors, including the history and culture of states; and benefits flowing from participation in specific regimes. The significant role of ethical factors gives a boost to normative theories about compliance. The role of systemic interests illustrates the benefits of a multilateral, institutional, and rule-based system. Among the factors militating against compliance, the dominant factor was state interest. Many former officials suggested that decisions about compliance involve a cost–benefit assessment, a consideration of many factors including international law. The chapter concludes by considering the former officials’ perceptions about the reasons that states outside of the United States take into consideration regarding compliance with international law.

Chapter Four focuses on US compliance with international law. The perception of former officials was that US compliance with international law was robust. When asked about the reasons that the United States complies or does not comply with international law, the former officials’ responses tracked many of the factors they listed for states in general. The chapter then explores the interplay between law and policy, exploring how policymakers balance these competing concerns. Former officials were clear that while international law was generally followed, it was not always dispositive. Legal issues were considered as one factor among a variety of factors, essentially involving a cost–benefit analysis. The salient considerations driving compliance or noncompliance, as revealed in the interviews, appeared to be the nature of the national interest or policy at stake; the nature and significance of the international legal rule involved ethical considerations; the views of allies; the ambiguity or precision of the legal obligation; and the weight of domestic political and bureaucratic concerns. The chapter next examines factors that may affect policymaker perceptions, including party affiliation, and concludes with a description of instances where the United States either bent international law or complied scrupulously.

Chapter Five examines the role of international law in State Department policymaking. It describes the formal and informal decision-making processes within the State Department, focusing on the influential role of the Legal Adviser and the Legal Adviser’s Office. The chapter then examines closely the weight given by policymakers to legal advice and the nature of the interaction between policymakers and lawyers. Policymakers, at least at higher levels, generally have final decision-making authority, but the views of the Legal Adviser’s Office can be determinative in the relatively rare instances when the lawyers deem a course of action conclusively illegal. Otherwise, the lawyers’ advice is influential, but its weight may vary depending on the circumstances, including the nature of the national interest involved. Many former officials indicated that the development of policy was often a collaborative and constructive process. The lawyers were usually willing to work with policymakers, and they were often willing to find alternative courses of action within the law, though they would not usually budge on an interpretation of the law. Some former officials indicated that their relationship involved greater contestation, resembling a negotiation. When international law conflicted with significant policy interests, policymakers could sometimes seek to overcome those obstacles.

The Introduction sets the context for the book and outlines the importance of its focus on sustainable development in international law. It offers background details and speaks to the inspiration for this book. These motivations derive from my professional experiences and research on international and environmental law in Africa and elsewhere. These experiences shaped my reflections on the history, the present state, and the future of the legal dimensions of the concept of sustainable development within international law.

The Introduction lays out the contextual background to the themes and elements that are brought together to shape the monograph’s arguments. It positions the monograph within the existing literature on the Seven Years’ War and the history of neutrality in order to establish how it builds upon these bodies of work to incorporate law as a necessary element of strategic analysis. The core hypotheses and arguments of the book are also established. First, that neutrality was a dynamic role for maritime nations such as Spain and the Dutch Republic which had as much of an influencing effect on British strategic thinking as did affairs with belligerent nations. Second, that the Court of Prize Appeal played a critical role within the three-pronged maritime strategy of maintaining foreign confidence in British maritime law and its court system; balancing the interests of British privateers and neutral carriers of commerce in the prize court system; and destroying French seaborne trade through commerce predation. Third, that British maritime strategic concerns shaped and created new legal rules, norms, and precedents within the prize court system that would then serve to clarify and cement British, Spanish, and Dutch understandings of neutral rights and international maritime law.