In the last few years, states have advanced various proposals for cooperation in the use of countermeasures. In this Article, we ask whether, and if so under what conditions, states may lawfully collaborate in the taking of countermeasures against other states. We distinguish five different types of collaboration: (1) independent but coordinated action; (2) secondment; (3) joint action; (4) aid and assistance; and (5) what we term “proxy countermeasures”—the idea of taking a measure at the request and on behalf of another state. We consider the permissibility of each, both where the acting state is itself entitled to resort to countermeasures and where it is not. We also draw attention to certain legal and policy considerations relating to, and to plausible avenues for, the development of international law.

Despite recent and increasing attention to the wrong of apartheid in international politics, some basic definitional questions remain uncertain. This article seeks to delineate the definition of apartheid in international law. Its focus is on the prohibition of apartheid binding States in custom and the obligation in Article 3 of the International Convention on the Elimination of All Forms of Racial Discrimination. In both cases, the article shows that the Apartheid Convention of 1973 supplies the wrong's definition. Thereafter, the article addresses three key elements that will be central to determining an allegation of apartheid: its wrongful acts, its distinctive purpose requirement, and the issue of what constitutes a ‘racial group’. Finally, the article also draws attention to the wider importance of the prohibition of apartheid in the international legal system. International law marks with particular normative significance a set of practices entailing systematic and structural harms that need not involve violations of life or bodily integrity.

General Comment 36 of the Human Rights Committee, adopted in 2018, asserts that ‘States parties engaged in acts of aggression as defined in international law, resulting in deprivation of life, violate ipso facto article 6 of the Covenant.’ One question about this claim is whether it reduces incentives for compliance with international humanitarian law for States and their agents—incentives provided through the principles of belligerent equality and combatant immunity. It is argued that it does not do so—such a worry about incentives is not a reason to reject the claim in General Comment 36. In the process, it can also be shown that, if accepted, this claim is interesting in another way: it entails, in effect, a duty on States to prosecute acts of aggression insofar as they entail killing, as they often will. This itself is doctrinally innovative. As to who is to be prosecuted, it is the political and military leadership of the State. It is their decision to wage war unlawfully that renders the killings arbitrary.

Humanitarian actors sometimes have to decide whether to render assistance in situations that put them at risk of liability for aiding and abetting under international criminal law. This is the problem of the virtuous accomplice—the idea that knowingly contributing to the wrongdoing of others might, exceptionally, be the right thing to do. This article explains why the problem arises and clarifies its scope, before turning to criminal law in England and Wales and Germany to assess potential solutions. It argues that the best approach is to accept a defence of necessity—of justified complicity—and shows that such an argument works in international criminal law.

In 2012, James Stewart published an article in this journal. The piece – ‘The End of “Modes of Liability” for International Crimes’ – argued for the abolition of accomplice liability in international criminal law and the adoption of a unitary model of participation in crime. This article argues that Stewart's proposal is flawed. As a matter of moral responsibility, the distinction between principals and accomplices follows from the recognition of individuals as moral agents. Turning to ordinary criminal responsibility, neither practical benefits nor expressive benefits nor the mitigating effects of the distinctive institution of criminal sentencing justifies the abolition of the distinction between principals and accomplices. Moreover, despite the collective nature of many international crimes, international criminal law ought to strive to accurately differentiate, in the attribution of responsibility, among participants. Only a differentiated model of participation can accurately and defensibly capture the different ways that individuals contribute to wrongdoing.

All etiological studies of complex human traits focus on analyzing the causes of variation. Given this complexity, there is a premium on studying those processes that mediate between gene products and cellular or organismal phenotypes. Studies of levels of gene expression could offer insight into these processes and are likely to be especially useful to the extent that the major sources of their variation are known in normal tissues. The classical study of monozygotic (MZ) and dizygotic (DZ) twins was employed to partition the genetic and environmental influences in gene expression for over 6500 human genes measured using microarrays from lymphoblastoid cell lines. Our results indicate that mean expression levels are correlated about .3 in monozygotic (MZ) and .0 in dizygotic (DZ) twins suggesting an overall epistatic regulation of gene expression. Furthermore, the functions of several of the genes whose expression was most affected by environmental effects, after correction for measurement error, were consistent with their known role in mediating sensitivity to environmental influences.