This chapter introduces an idea that has enjoyed a remarkable, if hotly contested, development in the post-Cold War era: humanitarian intervention. Based on a commitment to principles of humanity and respect for life, such action seeks to alleviate the unnecessary suffering caused by violent conflict through intervening in another state, with force under limited conditions. The chapter outlines the origins of humanitarianism and the history of humanitarian intervention before discussing the shift to the responsibility to protect (R2P). As world politics becomes ever more complex, debate about global responsibilities to protect suffering strangers will continue to shape the theory and practice of international relations. While abuse of human beings has not become less widespread, the preoccupation with COVID-19 and domestic priorities meant that little consideration was given to robust action against middle powers perpetrating mass atrocities in such places as Myanmar and Tigray, let alone against major powers in Ukraine and Xinjiang.

Chapter 7 examines the legality of humanitarian intervention and the extent to which certain interventions might qualify as being excused despite the lack of a legal basis.

Chapter 10 focuses on the somewhat controversial doctrine of humanitarian intervention. It assesses the issue of whether the doctrine can be reconciled with the UN Charter, before examining state practice in connection with the doctrine, including taking a look at Cold War and post-Cold War practice in assessing the position of the doctrine during the UN era. Given that the forcible entry by the North Atlantic Treaty Organization in the Kosovo crisis in 1999 proved something of a landmark in terms of events that have shaped the path of the modern doctrine, the status of the doctrine in the immediate aftermath of this intervention is given particular attention, as well as the impact that the war in Ukraine has had and whether there is an obligation to intervene in the context of genocides. The chapter then looks at the Syrian civil war and the relevance of the doctrine of humanitarian intervention to that particularly tragic conflict, which continues at the time of writing. A conception of the doctrine that has come to dominate contemporary debates is that of the ‘Responsibility to Protect’. Given its relatively recent rise to prominence, its impact upon the doctrine of humanitarian intervention is assessed.

This chapter discusses whether and in what circumstances states can resort to the use of force

After 2011, the Syrian opposition took on the Assad government directly through military means and indirectly by establishing pockets of rule beyond the government’s reach. As rebels took control of many government-held locations, they sparked the establishment of insurgent governing institutions in hundreds of communities. Local opposition-run institutions in the form of civilian-led local councils proliferated, dotting the provinces of Aleppo, Idlib, rural Damascus, Raqqa, Hama, and Homs. They worked to deliver basic relief and restore public services, sometimes in collaboration with, but often operating separately from, their armed counterparts. The boundaries of this “political marketplace”1 grew increasingly porous as a number of foreign states and private actors directly championed clients of their choosing, bolstering their favorites with financial and military support.2

Protest in the face of authoritarian rule necessitates a kind of audacity rarely, if ever, called for in daily life. When uprising turns to revolt and revolt to civil war, new questions arise: What comes next? What combination of suffering and joy does the future hold? And to whom should one now turn to manage those matters previously entrusted to the state? Even as new political possibilities arise, the stuff of ordinary life does not disappear but instead must be managed on terms that are both newly expansive and constrained. As people confront the hopes and hardships that come with rebellion, bread must be baked, crimes punished, and garbage collected.

This chapter focuses on peacemaking between the Allies and the Ottoman Empire after the signing of the armistice in 1918 and how it relied on the idea of minority protection and humanitarian intervention that dated back to nineteenth-century treaty agreements and diplomatic dealings.

This chapter covers the international law governing the use of force between states – the jus ad bellum. This is in contrast to the jus in bello – the law of armed conflict, or international humanitarian law – which regulates the conduct of hostilities once under way (see Chapter 11). Since at least 1945 the use of force by states has been prohibited, except in self-defence or when authorised by the United Nations Security Council. This chapter analyses the prohibition, the two exceptions, and the controversial issue of humanitarian intervention and its close relative, the ‘responsibility to protect’.

The chapter examines the ICJ’s contribution to the law on the use of force. The author considers the Court’s case law on the prohibition of the use of force and its potential exceptions, most notably the law on individual and collective self-defence. He identifies the main conceptualisations, inconsistencies, disagreements, and limitations of the Court’s opinions, arguing that although the Court initially had a significant influence, it has faded significantly over the years as a result of what appears to be a conscious or strategic decision of its judges.

Over the past few decades, it has become increasingly difficult for major powers to translate battlefield victories into favourable political outcomes. As a result, US military engagements in the Middle East, Russian engagements in its “near abroad” and in Syria, French engagements in sub-Saharan Africa, and the African Union’s war in Somalia have turned into protracted missions with little prospect of decisive victory. This chapter examines the phenomenon of “endless war,” asking why it has become so difficult to bring wars to an end and what can be done about it. It shows that the problem is global, rooted in the changing nature, purposes, and attitudes of war. As wars become less about resolving disputes between states and more about the internal composition of states, and as those contests become ever more internationalized, the capacity of actors to sustain war have increased while incentives to pursue peace have declined. The first part examines the “endless war” thesis that grounds the problem in US liberal hegemony. The second part offers a brief explanation of factors that extend a war’s duration and inhibit peace. The third discusses how these issues might be addressed.

How can force be used to pursue human security? Treatments of this issue are surprisingly rare.  This chapter addresses the potentially positive uses of force to address basic human needs under the new doctrine of human security in international law.   International laws, cases, and regimes addressing the constituent elements of human security are addressed in turn: personal and political security, economic, food, health, community and environmental security. The evolving structure and function of UN Peacekeeping Operations is demonstrated through cases of specific missions. Finally, the possibilities of 2001’s "Responsibility to Protect" doctrine are debated.

This chapter argues that an adequate account of group rights requires an embedded understanding of moral duties and rights within the context of common action for a common good. Drawing from Alasdair MacIntyre, I explain why group agency for a common good, through various social practices, grounds a framework of natural justice with correlative duties and rights, including various group moral rights. This account of natural justice is completed by an appeal to the common agency of an institutionalised political community for a political common good. I argue that human rights are a subset of moral rights, which ‘cry out’ as a matter of justice for political enforcement or realisation, whether against violations of fundamental natural law precepts or dereliction of core political responsibilities. These include group rights where the protected aspects of personal human flourishing are pursued through the common action of groups, such as families, trade unions, religious communities, and political communities. Moreover, group rights are essential to human rights – human rights presuppose the group moral right of political authority to administer justice for the common good.

Chapter 2 considers legal uncertainty in the jus ad bellum as defined in the UN Charter and other sources of law. It describes paradigms, framing this law around ‘plain cases’ of lawful and unlawful force. Supervaluationism describes paradigms as determined not by one but several tests, overlapping but not co-extensive - cases may meet all or only some tests. Fuzzy logic refutes binary distinctions between lawful and unlawful force, arguing these are end-points of a continuum, separated by a ‘penumbra of uncertainty’. The chapter outlines ‘hard cases’ of force, different to cases the UN Charter most obviously prohibits: anticipatory self-defence, pre-emptive self-defence, self-defence against non-state actors, humanitarian intervention, use of force to prevent WMD proliferation. The chapter describes how interviewees and survey participants evaluated such justifications, the results displaying the vagueness already identified. The chapter identifies one possible explanation: lawyers align with different ‘interpretive cultures’, holding different opinions about valid legal tests and interpretive techniques. ‘Restrictivists’ prefer ‘formalist’ interpretation techniques, while ‘expansionists’ prefer ‘dynamist’ interpretation techniques.

This chapter introduces the jus ad bellum: the rules of law determining when states may resort to war or, more broadly, the use of armed force. These rules must be distinguished from the jus in bello: these are the rules of law that apply in armed conflict (known as international humanitarian law). In order to put the current jus ad bellum rules into perspective, the chapter begins by introducing the concept of collective security and demonstrating how this was applied during the League of Nations era. The following sections set out the relevant rules of the UN Charter on the prevention and regulation of recourse to the use of force, with a particular focus on the prohibition on the threat or use of force. The chapter also discusses the collective use of force, meaning the use of force authorized by the Security Council, and the unilateral use of force in self-defense. Finally, the chapter examines whether new exceptions to the prohibition of the use of force are emerging -- in particular, humanitarian intervention and the responsibility to protect.

This chapter introduces the jus ad bellum: the rules of law determining when states may resort to war or, more broadly, the use of armed force. These rules must be distinguished from the jus in bello: these are the rules of law that apply in armed conflict (known as international humanitarian law). In order to put the current jus ad bellum rules into perspective, the chapter begins by introducing the concept of collective security and demonstrating how this was applied during the League of Nations era. The following sections set out the relevant rules of the UN Charter on the prevention and regulation of recourse to the use of force, with a particular focus on the prohibition on the threat or use of force. The chapter also discusses the collective use of force, meaning the use of force authorized by the Security Council, and the unilateral use of force in self-defense. Finally, the chapter examines whether new exceptions to the prohibition of the use of force are emerging -- in particular, humanitarian intervention and the responsibility to protect.