|dc.description.abstract||The effect of international law (IL) in national legal systems has always been of interest to legal scholars and practitioners as well. In recent times, attention has increased with the growing scope of IL. Accounts of the interrelations of IL and national law, however, more frequently investigate merely the impact of international treaties. On their face, the issues with treaties are most pressing since many treaties now have internal application and provide for sophisticated compliance mechanisms which may include compulsory jurisdiction of international judicial bodies.
As for customary international law (CIL), authors more often merely refer to a "monist" approach which holds that CIL is "part of the law of the land". The issues here are maybe less apparent but perhaps equally pressing. The formula "CIL is part of national law" leaves as many questions as the formula "treaties are not part of national law". These questions include: How does CIL become part of national law? What kind of law is it? Which law is to prevail in cases of conflict between CIL and national law? Moreover, and most importantly, CIL is unwritten law whose content has to be established before it can have effect. Here, questions of jurisdiction and methods to ascertain rules of CIL arise.
This thesis attempts to evaluate the effect of CIL in various common law systems. It therefore investigates and compares judicial practice in Australia, Canada, New Zealand and the United Kingdom to find the most appropriate solution.
Chapter one provides an introduction to the setting of the problem: the relation between IL and national law. It introduces the major theories and argues that neither of the theories is apt to explain all the issues that practically arise.
The remainder of the thesis will be organised in three parts.
The first part, comprising chapters two and three, investigates and evaluates various mechanisms to validate CIL nationally. Starting with a historical account of the English doctrine, possible points of departure in the other jurisdictions are identified.
The second part is occupied with the identification of rules of CIL in national courts. Chapter four shows that national courts are fit to ascertain rules of CIL and investigates which kinds of material should be used. Chapter five explores various mechanisms of national procedure available to obtain such material.
The third part deals with the application of CIL in national law. Here, chapter six identifies two ways in which CIL can be indirectly relevant for national law, that is by way of interpretation of pre-existing law or by reference from national law to rules of IL. Chapter seven investigates the rules that apply when CIL is in conflict with national statute or common law and links these rules to the validation mechanisms identified earlier. Finally, chapter eight provides a case study for the application of international criminal law in national legal systems.
In the concluding chapter, the above formula is found viable but merely explaining the basis of a comprehensive reference norm that allows for significant influence of CIL in national law.||