Facts Matter : a Study into the Casu

This dissertation is a study into the casuistry of substantive international criminal law. It analyses how international criminal courts use the facts of individual cases to shape and develop individual criminal liability for international crimes – that is, war crimes, crimes against humanity, genocide and the crime of aggression. Chapter I is the prologue to the study. It sketches the background of the research and sets out the hypotheses that underlie it. The basic starting-point of the dissertation is that substantive international criminal law constitutes an open legal system. It is composed of statutory and customary rules that define international crimes and modes of liability in relatively abstract and indeterminate terms (such as ‘superior’, ‘inhumane acts’, or ‘armed conflict’). In this way, the rules attain a so-called ‘open texture’ that makes it difficult to determine which cases fall within the scope of the law and to apply the law deductively. International criminal courts – such as the International Criminal Tribunals for the former Yugoslavia and for Rwanda (ICTY and ICTR, respectively) and the International Criminal Court (ICC) – accordingly play an important formative role. In particular in hard cases that are outside the law’s regular scope of application, the courts have leeway to discover and develop the law on a case-by-case basis. Thus, they can give shape and substance to rudimentary international crimes and modes of liability and have the ability to adapt these concepts to the realities of modern warfare. The openness of substantive international criminal law can be appraised positively insofar as it enables courts to do justice to the specific circumstances of individual cases, to adapt the law to changed conditions, and to progressively advance criminal responsibility for international crimes. At the same time, the law’s susceptibility to change and its opportunities for creative progress also generate a certain degree of uncertainty and fluidity. This creates the risk that courts apply the law in an irregular, unforeseen, or incomprehensible way subject to the personal intuitions of individual judges. To prevent such Einzelfallgerechtigkeit, the international principle of legality requires that courts carefully explain and justify their findings according to so-called ‘secondary rules of adjudication’. These rules stipulate normative standards that regulate when and how courts have to clarify the reasons underlying their decisions. This study focuses on the normative standards that control the way in which courts substantiate the classification (of the specific facts) of individual cases under general legal rules. Insights from casuistry are particularly relevant in this respect. Casuistry takes as a starting-point that the law is inextricably linked to its practical function. This implies that the meaning of the law is not determined by abstract rules alone, but develops in interplay with the questions and issues raised in individual cases. SUMMARY