This chapter examines some further difficulties in interpreting the meaning of state neutrality in the context of prenatal selection practices, and that are tied to the state’s approach to disability. A first set of difficulties relates to the challenging or impossible task of identifying a value-neutral definition or concept of disability. If such a definition cannot be found, it is certainly hard to see how the liberal and neutral state can act, although a review of liberal commitments can indicate that certain approaches are more neutral than others. A second set of difficulties is associated with the fact that many parents of disabled children feel that some of their most important values change after their child is born, though they could not have anticipated or understood this change in advance. This common experience, which could be a type of transformative experience, suggests that prospective parents might not be able to make an entirely rational and informed choice, and that the state’s supposed support for autonomy might need some qualification.

When engaging in interpretation, Human Rights Bodies (HRBs) may follow specific methods of treaty interpretation – including those derived from Articles 31–31 VCLT – or not. Moreover, the interpretative pronouncements of HRBs may themselves be considered authoritative pronouncements for the purpose of subsequent interpretation of human rights treaties or other sources of human rights law, frequently under the framework of ’pronouncements of expert bodies’. Such pronouncements may then be considered by interpreters as examples of either subsequent practice in the interpretation of treaties within the meaning of Articles 31-32 VCLT, or as ‘subsidiary means’ for the determination of rules of international law in the sense of Article 38 ICJ Statute. In light of this, and given expertise and volume of interpretative pronouncements of HRBs they need to be taken seriously when it comes to the determination of content of human rights rules. However, at present it is not yet clear whether these pronouncements can be relied on as means of interpretation via the formal avenues available in international law.

The International Committee of the Red Cross (ICRC) is the guardian of international law. Therefore, the Commentaries to the Geneva Conventions produced by the ICRC present an authoritative guidance on how these treaties are to be interpreted. In this sense, the ICRC represents an actor whose interpretation is authoritative on its substantive merit. A study of the interpretative methodology behind the Commentaries of the ICRC reveals that although the methodology has evolved it has done so apace with the evolution of the rules of treaty interpretation in general public international law – culminating in the adoption of the VCLT. This is argued to be decisive proof that the rules of international humanitarian law are subject to the same interpretive rules as other international rules.

While Chapter 1 was focused on the importance of reproductive choice for the modern liberal state, this chapter examines whether a liberal commitment to neutrality would require that the state place certain constraints on choice, for the benefit of the future child. The chapter begins by considering a hypothetical scenario put forward by Bruce Ackerman, where decisions are made by a Master Geneticist according to a liberal commitment to neutrality, and then analyses arguments made by proponents of liberal eugenics. In so doing, it scrutinises a number of complexities surrounding a state concern for the interests of the future child. A first set of complexities relates to the nonidentity problem, given that it is not clear that a liberal state should be concerned with the interests of a hypothetical replacement child. A second set of complexities relates to the gendered impact of the state’s concern for the child, and to the risks involved for women’s bodily integrity and equality.

International law, like any other legal system, must ensure legal certainty. This task is all the more important for international law in light of the constant criticism advanced towards the nature of this legal system. One of the key tools to ensure legal certainty is a consistent and coherent application of rules based on a method of interpretation, where that method serves as the backbone of a judgement. The legal system and an act of application of a specific rule gain persuasiveness and legitimacy where the use of the method of interpretation of a rule is consistent from one case to another. Judges are the guarantors of the resilience of law in the sense that it is in their power to ensure its impartial and uniform application, which in turn counters allegations of inefficiency or bias of that system of law. All these considerations about the systemic features of interpretation and the role of judges as interpreters play toward at least a perception of the rule of law in the legal system. Therefore, the general rule of interpretation of international law is a central element in the international rule of law.

This chapter analyses the law in two areas that relate to prenatal selection, with the aim of critically evaluating what ‘messages’ the law might express about disabled lives, and about the state’s position: first, the law on abortion on the grounds of disability under the Abortion Act 1967, and second the law in the United Kingdom on preimplantation genetic testing (PGT). In the first case, it is argued that the disability ground in the law on abortion is not primarily protecting reproductive autonomy, but rather reflects a negative view about the value of disabled lives. In the second case, it is argued that the identification of approved conditions for PGT does not reflect a neutral approach to the definition of disability, and that the legal regime includes elements of state coercion. The chapter also examines a third area which does not relate to prenatal selection, but which might shed light on the state’s position about the latter: court decisions about the treatment of very ill infants. Here, there are reasons to think that interpretations of the best interests of the child do not, in fact, necessarily only take into account the interests of the child.