The lawfulness of carbon border adjustment measures (CBAMs) under general international economic law and particular economic agreements is explored; specifically, if their international lawfulness can be determined by thinking of them as countermeasures necessary to implement climate change obligations. As there are no non-discriminatory obligations under customary international law, it is argued that CBAMs are lawful under general international law, but under particular international economic agreements they can be seen as countermeasures lawfully taken in response to breaching the obligation to curb GHG emissions, allowing their justification as a breach of primary non-discriminatory economic obligations, particularly the national treatment principle under the GATT and GATS. This shifts the burden of proving necessity/proportionality to the State in breach of the obligation. CBAMs are fundamentally lawful measures and can only give rise to compensation if it they are unnecessary/disproportionate. This chapter also assesses whether they can be thought of as erga omnes contractantes obligations under international economic agreements, particularly the GATT and the GATS.

This chapter explores the availability of the customary defence of countermeasures to investment disputes brought before investor-state arbitral tribunals. It scrutinises the tribunals’ reasoning and the parties’ arguments in the cases of Archer Daniels Midland, Corn Products International and Cargill. It discusses their approach to the customary requirements for a lawful countermeasure and to the limits of their own jurisdiction ratione materiae and ratione personae. The chapter aims to discern firstly, whether CIL or the text of current investment treaties precludes responding states from invoking the defence of countermeasures in the context of an investment dispute. In this context, the chapter also offers some insights into the approach of arbitral tribunals to the customary requirements for the successful invocation of countermeasures. Secondly, it discusses whether the subject-matter and personal jurisdiction of arbitral tribunals precludes the tribunals from examining and applying the defence of countermeasures. The chapter argues that CIL does not preclude the applicability of countermeasures to investment disputes. It further argues that current investment treaties do not exclude, explicitly or implicitly, the defence of countermeasures.

In this chapter, Daniel Franchini and Russell Buchan examine the status, nature, content, and scope of the obligation of peaceful dispute settlement. This chapter traces the emergence of this obligation under customary and conventional international law, analyses the conditions that trigger its engagement, and explores what measures disputants must take in order to discharge this obligation. This chapter maintains that the peaceful settlement obligation is an interstitial norm insofar as it influences the interpretation and application of other rules of international law relevant to the peaceful settlement of disputes.

Even the most carefully developed and tested vaccine can lead to injuries. Such injuries can disproportionately affect vulnerable populations who are most in need of vaccinations but are also at risk of financial ruin if harmed by a vaccine. Fortunately, injured parties can usually recover expeditiously through the National Vaccine Injury Compensation Program (VICP), which has no damages cap. In the case of many injuries, causation is presumed if a claimant’s symptoms arise within a certain time, leaving only the amount of damages in question. By contrast, individuals injured by a vaccine approved under an emergency use authorization (“EUA”) can access compensation only under the Countermeasures Injury Compensation Program (CICP), which is far less generous and accessible. It compensates only the most serious injuries, requires a higher burden of proof, has a one-year statute of limitations from the date of vaccination, and limits damages awards. During a pandemic, such as COVID-19, vaccines are likely to be approved under an EUA. This chapter highlights the absence of VICP compensation for vaccines with an EUA and analyzes its ramifications for disadvantaged populations. The chapter also proposes legal changes to rectify this wrong. One is an amendment to the PREP Act that would add vaccines with an EUA to the VICP. The second is an entirely new vaccine fast-track approval process that would keep these vaccines in the VICP and would ensure that sufficient data is generated from clinical trials to allow the vulnerable to make informed vaccination choices.

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.

When a treaty prescribes how disputes can be settled, it usually provides for a preliminary phase involving direct negotiations or consultations. In the case of bilateral agreements, more binding mechanisms tend to be found in agreements with more specific obligations, or those directly affecting individual interests, such as trade. Otherwise, bilateral agreements will often specify that disputes are to be resolved by the diplomatic channel or other avenue of voluntary settlement. Both bilateral and multilateral treaties may provide for conciliation or mediation. The parties may, however, wish to resort to compulsory binding settlement. The two principal features are a prior agreement to submit disputes to a third party, and a provision that the decision of the third party is legally binding on the parties in dispute. Procedures of arbitration and judicial settlement, including the International Court of Justice, are analysed. In respect of remedies, the chapter examines countermeasures and the principles underlying them, sacrosanct obligations and necessity.

This chapter addresess the operation of reciprocity in the enforcement of international law. It looks at the roles reciprocity may play in the consequences of a breach of international law, analyzing the exception of nonperformance and State responsibility. In particular, it analyzes the consequences that attach to the breach of erga omnes obligations or peremptory norms, and the rules and limitations on countermeasures. The structure and mechanisms of international responsibility demonstrate the persisting importance of reciprocity in international law and the structural limitations that international law’s horizontal nature poses to establishing specific consequences for breaches of community obligations.

The present chapter examines whether, and if so to what extent, customary international law applies within the internal legal sphere of the EU, that is, between EU member states within the EU law’s scope of application as well as in their legal relations to the EU. In essence, the relevance of customary international law within the EU’s internal legal sphere is about the EU’s assertion of autonomy and self-containment that has been unfurled by the CJEU. The analyses of key areas of customary law (e.g. diplomatic relations, sovereign immunity and equality, rules of responsibility) reveal a complex picture of the its rules’ relevance within the EU. They play a more tangible role in the relationship between EU member states, first and foremost in sovereignty-related areas, than in member states’ legal relationships to the EU. Nevertheless, the present chapter shows that despite being a ‘new legal order’, the EU treaties still constitute a subsystem of public international law, albeit one which manifests typical characteristics of self-containment.

US, Finland and Ireland, in response to China’s National Security Law, suspended their extradition treaties with Hong Kong. France stated that it would not be ratifying an extradition treaty with Hong Kong. These suspensions ostensibly were intended to safeguard the rights of nationals (and others) in the suspending States. In some cases such as the UK the same act could constitute retorsion, meaning that it could have been intended as a patently lawful (albeit less than friendly) reaction to the National Security Law. Thus, a foreign State – albeit apparently not the UK which, as a party to the Sino–British Joint Declaration, had declared a breach of the Sino–British treaty – could still treat the National Security Law as Beijing’s lawful prerogative, or in any case may have no clear legal right to press, yet still react with a perfectly lawful act of its own to show its displeasure.

The rules of state responsibility are set out in the International Law Commission’s (ILC) Articles on the Responsibility of States for Internationally Wrongful Acts. This chapter introduces the basic features of the ILC’s Articles on State Responsibility, beginning with an explanation of what constitutes an internationally wrongful act. The following section discusses the circumstances precluding wrongfulness that may be invoked by states seeking to avoid responsibility for an internationally wrongful act. The chapter then covers the aftermath of an internationally wrongful act, which can involve legal consequences, such as reparations, as well as countermeasures. This chapter focuses specifically on the responsibility of states, rather than the responsibility of international organizations or individuals.

The rules of state responsibility are set out in the International Law Commission’s (ILC) Articles on the Responsibility of States for Internationally Wrongful Acts. This chapter introduces the basic features of the ILC’s Articles on State Responsibility, beginning with an explanation of what constitutes an internationally wrongful act. The following section discusses the circumstances precluding wrongfulness that may be invoked by states seeking to avoid responsibility for an internationally wrongful act. The chapter then covers the aftermath of an internationally wrongful act, which can involve legal consequences, such as reparations, as well as countermeasures. This chapter focuses specifically on the responsibility of states, rather than the responsibility of international organizations or individuals.

Section B provides an overview of certain important preliminary legal matters that are of relevance to any discussion of nuclear weapon issues. They include sovereignty and certain aspects of the law of State responsibility, including countermeasures.

Chapter 17 attempts to pin down a moving target, cyber and its use and utility in armed conflict. The cyber targets chosen by China, Russia, Iran, and North Korea are detailed. The chapter defines cyber “attacks,” differentiating them from cyber “operations” – akin to a felony-misdemeanor distinction. Cyberattacks are found to be a use of armed force, in the sense of UN Charter Article 2(4), raising the right of victim states to respond with armed force in self-defense. Potential cyber conflicts are classified as international or non-international based upon their perpetrators. The difficulties of attribution of cyberattacks are detailed, including sovereignty and military necessity. A counter to cyberattack is belligerent reprisal, which is explored. Cyberattacks on critical national infrastructure (CNI) are a major problem. After defining CNI, the US position on responses is discussed. Recent changes in US cyber policy authorize far greater cyber retaliation and reprisal, as well as providing federal funding to carry them out. Finally, CNI’s weak link, the unwillingness of civilian corporations to fund their own cyber protection, is noted.

Coercively inducing oppositional TG so as to trigger a regime change is in principle prohibited under international law. Does this hold true in the most extreme circumstances, i.e. when the incumbent power violates ius cogens? If states wish to halt gross and persistent breaches of ius cogens, they must exhaust the available multilateral fora and respond through collective non-recognition; multilateral cooperation; and peaceful settlement including by directly negotiating with the ius-cogens-violating regime committing these breaches. If these steps fail, international law does not fully rule out the possibility of inducing oppositional TG as a last resort measure. Checks and balances, both procedural and substantive, are then to become integral part of the unilateral and coercive inducement of oppositional TG. But the chances of impeccable lawfulness are quite low in light of the stringent procedures and conditions that apply, forming the basis for an obligation of strict moderation.

A growing number of states have started pointing to the customary doctrine of countermeasures as the most feasible unilateral remedy in the case of a malicious cyber operation carried out by an adversarial actor. Thus, the legal requirements of successfully invoking a right to resort to countermeasures are analysed in depth. In particular, the chapter deals with state policies such as 'active cyber defences' and 'hacking back' as reactions to cybersecurity incidents, and their lawfulness as countermeasures. After examining the pervasive problem of attribution in cyberspace, the states' duty to prevent malicious cyber operations emanating from their territory and the standard of due diligence in this regard are investigated. The chapter concludes with considering the invocation of countermeasures for the purpose of guarantees of non-repetition and reparation in the aftermath of a cybersecurity incident.