In the last solo-authored edition of his seminal book, International Dispute Settlement, the late Professor John Merrills wrote that ‘the peaceful settlement of international disputes is the most critical issue of our time’.1 To the casual reader, this statement may seem an exaggeration. Surely the environment and climate change, collective security, global health, human rights, and international trade and finance, among others, may appear to be more pressing issues today. And yet, having devoted most of his professional life to the advancement of legal scholarship on international dispute settlement, Merrills was acutely aware that the study of this discipline offers the most effective litmus test to assess the strengths and limitations of international law at any given time. International disputes naturally arise whenever international law subjects disagree on matters of law or fact. Alongside disputes concerning territory and the use of force, today we witness an exponential growth of disputes on issues as diverse as human rights, environment, trade, and investment. Disputes are also becoming more complex, involving multiple parties, norms, and dispute settlement mechanisms (diplomatic or adjudicatory). At the same time, international disputes and the process of dispute settlement can act as a catalyst for the enforcement but also the development of international law. Dispute settlement and its institutions reaffirm existing norms and stabilise legal relations, but can also contribute to the crystallisation of new norms or new interpretations of existing norms because international disputes and their processes of settlement may evidence gaps or shortcomings of existing norms.

In this chapter, Nicholas Tsagourias and Fiona Middleton examine the role of fact-finding in ascertaining the facts supporting cyber attribution claims. More specifically, it considers the modalities of fact-finding, discusses the challenges it is encountering in the context of cyber attribution, and assesses the proposed cyber attribution mechanisms. The chapter concludes by identifying certain key features a cyber attribution fact-finding mechanism should exhibit to perform its tasks effectively and contribute to the settlement of cyber attribution disputes.

This chapter addresses the scope of regulation of means and methods of warfare generally and then examines the prohibition of weapons causing superfluous injury or unnecessary suffering, indiscriminate weapons, and weapons harming the environment. It then turns to the regulation of certain weapons, namely nuclear weapons, cluster munitions, UAVs and autonomous and automated weapons systems. The chapter goes on to review the regulation of certain methods of warfare, perfidy and ruses of war, pillage, espionage and improper use of protected emblems. It then discusses weapons review before addressing targeting, military objectives, proportionality in attack and precautions. The chapter closes with discussion of cyber warfare in this context.

This chapter reviews the enforcement of IHL through a range of legal and non legal mechanisms. It first addresses the obligation to respect and ensure respect for IHL, protecting powers, the international humanitarian fact finding committee and the role of human rights bodies. State responsibility, state immunity and acts of state and political question doctrines are then discussed. Reparations, including state reparations, individual reparations and reparations by armed groups are then reviewed. UN immunity, UN enforcement and responsibility in peacekeeping operations, liability and reparations in peacekeeping operations and criminal responsibility in peacekeeping operations are also addressed. The use of belligerent reprisals in the enforcement of IHL and armed groups and enforcement of IHL is then discussed. In conclusion the chapter considers United Nations Action in enforcement of IHL.

The chapter addresses the definition of neutrality in the case of an IAC before discussing the rights and duties of neutrals. Neutrality involves specific duties which may be summarised as abstention, impartiality, prevention and acquiescence. It then reviews neutrals rights, principally inviolability of the neutral states territory. The chapter then goes on to consider neutrality and sea warfare, neutrality and air warfare and neutrality and cyber warfare.

The chapter begins with discussion of the definition of occupation, beginning of occupation, and the end of occupation. It then reviews the rights and duties of the occupying power under Hague Convention IV as customary law addressing public order and safety, security needs of the occupying power, amendment of domestic laws of occupied territory, prolonged occupation of territory and transformative occupation. The chapter then considers the use of lethal force in occupied territory, transfer of the ocupying powers population into occupied territory, deportation, detention and destruction of property. It then addresses the application of IHRL in military occupation and finally the analogous UN adminstration of territory.