Chapter 3 considers factual uncertainty in the jus ad bellum. It describes how the vagueness described in Chapter 2 can affect factual evidence in the jus ad bellum. Such situations are often chaotic, fast moving, involving actors trying to mislead, and where factual evidence is open to different interpretations. Tests such as necessity, imminence and proportionality require decision-makers to compare multiple forecasts of outcomes if force is used or not. Survey participants evaluating four fictional conflict scenarios, demonstrating how even fictional ‘facts’ elicit varying opinions. The ICJ’s rules of evidence only reduce rather than resolve factual uncertainty. The chapter suggests a second potential explanation for contestation in the jus ad bellum: lawyers resolve factual uncertainties and make forecasts using their politico-strategic and ethical intuitions, forming competing strategic cultures disagreeing about legality of specific cases and the jus ad bellum more generally. Thus ‘restrictivist’ lawyers prefer a ‘pacificist’ strategic culture, seeing little extra-legal justification for force, while ‘expansionist’ lawyers prefer an ‘interventionist’ strategic culture, seeing more such extra-legal justifications.

This chapter concerns the role of witnesses in litigation pre-trial and will focus on the preparation of affidavits and witness statements for use in trials but will also consider affidavits used in interlocutory disputes.1 Obtaining evidence from witnesses, both lay and expert, is one of the key procedures available in litigation which is absent from other forms of civil dispute resolution. Witness evidence is also one of the most time-consuming and expensive aspects of case preparation, particularly expert evidence as experts can be extremely costly.2 Expert witnessing has been the subject of considerable contention, reform and debate, both within the legal fraternity and in the broader community. The preparation of expert evidence demonstrates many of the key conflicts explored in Chapter 2.3, particularly the balancing of efficiency with due consideration. The preparation of witness evidence also engages with the key civil dispute resolution issues of access to justice and open justice. The time and expense associated with locating witnesses and preparing affidavits highlights the potential for the wealthy to be unfairly advantaged when preparing for litigation.

The chapter examines the crucial question whether the ECtHR recognizes that a reasonable hypothesis of harm is sufficient to establish the link between environmental harm and a specific risk to a Convention right required under the specific risk principle. The crucial ECHR rules on this point relate to evidence and the requirements for victim status under Article 34 ECHR. The chapter first sets out the general principles developed with respect to the rules of evidence and victim status before exploring some encouraging developments in more recent cases under Articles 2 and 8 ECHR. The chapter recognises the difficulties and limitations that arise for applicants who seek to obtain relevant evidence and records from reluctant states. Nonetheless, the ECHR case law generally comports well with the requirements of the environmental minimum. The ECtHR does not require applicants to demonstrate an irrefutable scientific link between the environmental harm and an impact on their rights: in many recent decisions the ECtHR is content with evidence of a general population level risk arising from the environmental harm expierienced by the applicant.

The UN Commission for Human Rights (UNCHR) created the WGAD in 1991 after a long investigation by the Sub-Commission on the Prevention of Discrimination and Protection of Minorities into the practice of administrative detention. In his final report to the sub-commission, prominent French lawyer Louis Joinet emphasized the need for “suitable machinery … to prevent and report violations” of international law regarding detention and recommended the UNCHR create either a special thematic rapporteur or a five-person working group. He thought the latter option “might be more effective, by being able to deal with the variety of categories of detention.”