11. Use of force

This chapter examines under what circumstances States may use armed force under customary international law and Arts 2(4) and 51 UN Charter. After noting that the use of armed force is generally prohibited and only limited to self-defence, and then only if the target State is under an armed attack, we show that several States have expanded the notion of armed attack. Besides self-defence, the Security Council may authorize the use of armed force through a process of collective security. Several examples of collective security are offered, as well as the ICJ’s position on what constitutes an armed attack. In recent years, the range of actors capable of undertaking an armed attack has included terrorists. Moreover, the development of the doctrine of the responsibility to protect is a significant achievement.

10. Peaceful settlement of disputes

This chapter examines the means and methods relating to the peaceful settlement of international disputes. The UN Charter obliges States to resolve peacefully their disputes and suggests certain means for such settlement: on the one hand, diplomatic means, like negotiation, mediation, conciliation, or the ‘good offices’ of the UN Secretary-General and, on the other, legal methods, such as arbitration and recourse to the International Court of Justice (ICJ), which are binding. The ICJ exercises its jurisdiction over contentious cases only upon the consent of the parties to the dispute, which may be expressed through various forms (e.g. compromis or optional clause declaration). The ICJ may also render advisory opinions to questions of international law posed by the UN General Assembly, the Security Council, or other competent organs and organizations. The chapter also explains dispute settlement in the context of international investor–State arbitration and in the World Trade Organization.

8. Law of the sea

The law of the sea governs the relations of States in respect of the uses of the seas. It allocates competences between, on the one hand, coastal States wishing to extend their jurisdictional reach as far as possible and the flag States, on the other, wishing to have the seas open for vessels to navigate and for other uses. The chapter discusses the laws applicable to each maritime zone, namely internal waters, the territorial sea, the contiguous zone, the Exclusive Economic Zone, the high seas, and the seabed. It also sets out the rules of maritime delimitation between States with opposite or adjacent coastlines.

5. Personality, statehood, and recognition

This chapter examines the meaning of international legal personality and the range of actors that possess such personality, namely States, international organizations, individuals, multinational corporations, and several other non-State actors. Given the centrality of States, the criteria for statehood are analysed, and both traditional and contemporary criteria are discussed. Article 1 of the 1933 Montevideo Convention is used for assessment of whether an entity satisfies these criteria which include: permanent population, a defined territory, government, capacity to enter into foreign relations, and the relevance of human rights. Competing theories regarding the role of recognition by third States as an element of statehood are also considered. Equally, the rights and duties of non-State actors are analysed in terms of capacity conferred upon them under international law.

1. The nature of international law and the international legal system

This chapter briefly discusses the nature of the international legal system. The premise is that the structure of the international legal system is fundamentally different from that of national legal order: contrary to the vertical structure encountered in domestic settings, in international law the structure is horizontal. States enjoy sovereign equality, while both international law-making and international adjudication are based on the consent of the States. There are various theories that have attempted to describe the nature of the international law, including naturalism, positivism, formalism, and realism. Also significant is the existence of a certain hierarchy in the international legal system, in the sense that there are some peremptory norms of international law, such as the prohibition of torture and genocide, to which there is no derogation.

9. State responsibility

The law of international responsibility sets out the legal consequences arising from a breach by a State of its international obligations. It should be distinguished from ‘primary rules’ of international law, which lay down international obligations. International responsibility arises when a certain act or omission is wrongful, i.e. it is attributed to a State and it amounts to a violation of its ‘primary’ obligations. The international responsibility may be excused under certain strict circumstances, like consent or necessity. Otherwise, the responsible State should cease the wrongful conduct and in case of damage, it should provide reparation to the injured State, in the form of restitution, compensation, and satisfaction.

7. Immunity

Immunity is a procedural bar whereby the courts of a country are precluded, while the immunity persists, from entertaining a suit, civil or criminal, against a person or entity. This chapter distinguishes personal from functional immunities and then goes on to demonstrate the difference between acts undertaken in a public capacity, which always attract immunity, and those undertaken in a private capacity, which do not as a rule attract immunity. The chapter shows that in recent years the characterization of an act as being of a public nature has been restricted by the practice of States and national courts.

3. The law of treaties

This chapter examines the rules of international law governing the birth, the life, and the death of treaties. Treaties, a formal source of international law, are agreements in written form between States or international organizations that are subject to international law. A treaty falls under the definition of the Vienna Convention on the Law of Treaties (VCLT) no matter what form or title it may have. The most important factor is that it sets out obligations or entitlements under international law. The VCLT enumerates the rules governing the ‘birth’, i.e. the steps from the negotiation until the entry into force of the treaty; the ‘life’, i.e. the interpretation and application of the treaty; and its ‘demise’, i.e. its termination. The two fundamental tenets are, on the one hand, the principle ‘pacta sunt servanda’ and, on the other, the principle of contractual freedom of the parties.

12. Human rights, international criminal and humanitarian law

This chapter examines the nature and diversity of human rights, rather than any particular right. It looks at issues such as the universality, interdependence, and indivisibility of rights. It points to the issue of justiciability and emphasizes the obligation of States in both its negative as well as its positive dimension. The chapter examines the role of derogations and reservations to human rights treaties as well as cardinal principles in such treaties, namely the margin of appreciation and the scope of application. The chapter examines the concept of international criminal responsibility and looks at the four core international crimes, namely grave breaches (war crimes), crimes against humanity, genocide, and the crime of aggression. Finally, the chapter examines in some detail the key aspects and distinctions in international humanitarian law, such as the distinction and legal consequences between combatants and civilians and others.

6. Sovereignty and jurisdiction

This chapter briefly looks at the nature of sovereignty and its parameters in international law, but essentially focuses on the function and nature of jurisdiction. It first examines the breadth of the space in which sovereignty is exercised; namely land, sea, and air. Thereafter, it assesses territorial jurisdiction (in both its objective and subjective dimensions) and examines the practice of the four extraterritorial principles of jurisdiction, namely nationality-based, the protective principle, passive personality, and universal jurisdiction. The chapter then considers instances where national courts refuse to exercise their ordinary jurisdiction, namely instances where the accused is covered by the privilege of immunity or because his or her arrest was illegal. Finally, it looks at the US practice of extraterritorial jurisdiction whereby sometimes the sovereignty of other nations has been breached.