This chapter considers self-help remedies, which involve the plaintiff making good her own rights without the intervention of the judiciary. The focus of this book is on remedies that are awarded pursuant to a judicial order. However, an exclusive consideration of judicial remedies would ignore the fact that most disputes are settled outside the courts and that most parties prefer non-judicial settlements. It may be queried whether self-help remedies are really remedies in the strict sense of the word. They do not involve a court order; instead, the court gives permission to a plaintiff to act in a particular way. Nevertheless, in a broader sense, the plaintiff is allowed to redress her grievance by vindicating her own rights. By allowing a plaintiff to redress her rights in this way, the law affirms and reinforces the importance of certain interests. As noted in Ch 13, Varuhas has observed that the interests protected by vindicatory awards are often associated with the torts actionable per se.

This chapter discusses defences, which are a fundamental part of criminal law, and reflect important limitations on the proper scope of punishable conduct. It is the purpose of this chapter to set out and critique the law relating to defences, in both treaty-based and customary international law. This chapter is concerned with substantive defences; it does not deal with issues such as immunity, youth, ne bis in idem, or limitation periods.

This chapter considers how and in what contexts the reasonable person standard was applied by the selected colonial courts of the British Empire. The key question is whether the reasonable person imported from England remained English in substance – whether it continued to resemble a man on the Clapham omnibus – or the courts tailored the standard to the specific circumstances before them. As the first section shows, there are many cases in which the reasonable person was equated with an Englishman. This suggests that the standard was static in nature. However, the second section of the chapter complicates this conclusion by introducing numerous cases and settings in which the standard was adapted to specific, local contexts – sometimes so successfully that local variants of it developed. Drawing together the first two sections, the final part considers the nexus between a standard’s resemblance to the people to whom it is applied and the authority of law.

Observing China’s use of force, its voting behaviours and argumentation in the UN Security Council (UNSC) and its official statements on other relevant occasions allows summing up the Chinese approach to jus ad bellum in the following aspects: a narrow meaning of the term ‘force’, a positivist interpretation of the threshold, time and target requirements of exercising the right of self-defence, a negative attitude towards humanitarian intervention and a strict reading of the responsibility to protect. These positivist tools have led China to consistently endorse a ‘restrictivist’ understanding of the UN Charter that prohibits any use of military force by one state against another absent authorization from the UNSC or a situation involving self-defence. In this sense, China would likely maintain its ‘wait and see’ approach regarding jus ad bellum in cyberspace. However, faced with the anonymity of cyberspace and the increasing frequency of cyber-attacks, the possibility that China will adopt a more flexible understanding of certain rules cannot be ruled out.

Chapter 6 provides an in depth analysis of the right of self-defence: its essence, dual legal basis and other aspects of its application, including the authorship of an armed attack, the modalities of application of self-defence and the role of the Security Council.

Chapter 8 seeks to untangle various issues in addressing when and how a state might be able to resort to the use of force in self-defence against non-state actors. It firstly raises some important general considerations in relation to self-defence against non-state actors, before moving on to examine the situation of self-defence measures which target both the non-state actors and the host state, as was the case with the United States’s response to the terrorist attacks of 11 September 2001. A distinction needs to be made between self-defence taken against both the non-state actor perpetrators of the attack or those posing a threat and the state within which they are located, and those actions that are more limited in only specifically targeting the non-state actors. The chapter finally addresses the particular phenomenon of so-called targeted killing, which engages not only the jus ad bellum, but also the legal framework of international human rights law and, potentially, international humanitarian law.

Chapter 6 provides an overview of the general aspects of the right of self-defence. It first examines the concept of an ‘armed attack’ as found in Article 51, with the aim of shedding some light on the difficult issues and questions raised by this prerequisite for the invocation of the right of self-defence. It then goes on to provide an examination of the twin customary principles of necessity and proportionality, including a specific look at the controversial concept of armed reprisals, before moving on to examining military action for the protection of nationals who are located abroad. The right of self-defence exists in both individual and collective forms, and the chapter takes a specific look at the right of collective self-defence. Finally, it examines the role of the UN Security Council in the invocation and implementation of the right of self-defence, an aspect of the right which is prominent throughout Article 51.

Chapter 5 has as its focus not the institution of peacekeeping per se, but more specifically the use of force within, and as a now an integral part of, United Nations peacekeeping. It begins by attempting to define UN peacekeeping, given its absence from the UN Charter, and goes on to address the legal basis for peacekeeping operations and the basic principles of peacekeeping. The chapter then traces the development of peacekeeping, from the early UN Charter-era operations, which saw the establishment of the basic principles, through to the challenges to these principles, which did not take long to manifest themselves, in particular through the use of forcible measures by peacekeeping forces. Finally, the chapter examines the evolution of the use of force within peacekeeping missions, from simple self-defence to the implementation and enforcement of robust mandates, and assesses not only whether the various forms of forcible peacekeeping can be reconciled with the fundamental principles of peacekeeping, but also whether peacekeeping has now taken on a war-fighting role.

The purpose of Chapter 7 is to examine the various forms of preventative self-defence, that is whether the right of self-defence can be invoked before an armed attack has been launched, or at least before the physical manifestations of one have begun to occur. Given that there have been no attempts at formal reform of Article 51, the question arises as to how, if at all, might preventative self-defence be reconciled with this key requirement of an armed attack. This chapter therefore examines the three main forms of preventative self-defence: interceptive, anticipatory and pre-emptive. All three have been of central interest in the light of contemporary threats and challenges. In this respect, while there has been a greater acceptance of the possibility to invoke self-defence in the face of the threat of an ‘imminent’ attack, there has been, as explored in this chapter, disagreement as to exactly whether this is restricted to being interpreted in its ordinary temporal meaning or whether it is today necessary to take it into other contextual factors.

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

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’.

Anti-satellite weapons that rely on violent impacts and create space debris are regarded as a major threat to the exploration and use of space, including the use of space assets for communications and Earth imaging. This chapter examines two ways in which the testing of such ‘kinetic’ weapons might already have become illegal. First, the accepted interpretation of Article I of the Outer Space Treaty may be evolving as a result of the changing practice of the parties to that treaty. In short, many states are behaving as if tests of anti-satellite weapons that create debris are contrary to the ‘freedom of exploration and use of space’. Second, the same practice and an accompanying opinio juris may be contributing to the development of a parallel rule of customary international law. This chapter also examines the legality of the use of kinetic anti-satellite weapons, as opposed to their testing. Two additional, separate bodies of international law are relevant here: the jus ad bellum governing the recourse to armed force, which includes the right of self-defence, and the jus in bello governing the conduct of armed conflict. A close analysis leads to the conclusion that any use of a kinetic anti-satellite weapon would be illegal today because of the growing crisis of space debris.

The chapter covers Germany’s perspective on the use of force, armed conflict and international humanitarian law, and arms control and disarmament. The first part addresses Germany’s position on the US killing of Iranian General Soleimani, Germany condemning Iranian missile attacks on US bases in Iraq and Germany refining the right of sustainable self-defence. The second part shows the German Federal Court of Justice reaffirming that there is no justification in international law for attacks by the Kurdistan Worker’s Party, the German government’s stand on foreign troop presence in Syria, Germany’s stand on the law of occupation regarding US forces in Syria, Germany considering Israeli settlement activities in the Occupied Palestinian Territories illegal, Germany’s view on drones, the Federal Constitutional Court affirming only States can claim compensation for violations of international humanitarian law, and the Federal Administrative Court ruling the US may continue to use its base in Germany. The third part covers Germany’s criticism of US anti-personnel landmine policy and Germany’s condemnation of North Korean missile tests.