This chapter examines the hierarchy of norms and sources in international law. Establishing a hierarchy of norms and sources allows for a community to elevate certain fundamental principles over ordinary norms, and to establish order and clarity in the relations between norms, authoritative institutions, and legal subjects. In the last half-century, a special class of general rules endowed with peremptory legal force has emerged. Known interchangeably as ‘peremptory norms’ or ‘norms of jus cogens’, these are regarded as possessing a higher status than ordinary rules of international law, and would prevail over the latter in cases of conflict. As such, whether an ordinary rule exists in treaty or customary law, or is a general principle, it is null and void if in conflict with a rule of jus cogens. The chapter also studies a related category known as rights or, more commonly, obligations erga omnes (‘owed to all’).
Chapter
This chapter examines the hierarchy of norms and sources in international law. Establishing a hierarchy of norms and sources allows for a community to elevate certain fundamental principles over ordinary norms, and to establish order and clarity in the relations between norms, authoritative institutions, and legal subjects. In the last half-century, a special class of general rules endowed with peremptory legal force has emerged. Known interchangeably as ‘peremptory norms’ or ‘norms of jus cogens’, these are regarded as possessing a higher status to ordinary rules of international law, and would prevail over the latter in cases of conflict. As such, whether an ordinary rule exists in treaty or customary law, or is a general principle, it is null and void if in conflict with a rule of jus cogens. The chapter also studies a related category known as rights, or, more commonly, obligations erga omnes (‘owed to all’).
Chapter
Paola Gaeta, Jorge E. Viñuales, and Salvatore Zappalà
This chapter deals with some fundamental realities of international law as a body of legal rules which traditionally requires implementation at domestic level through transposal. In so doing it discusses the traditional theoretical distinction between monism and dualism, as abstract approaches to the relationship between domestic and international legal order. It then tackles the issue of the effects (including direct effects) that international law may have in concrete situations within national systems, as a consequence of, or, in some instances even irrespective of, transposal through national legislation. Thirdly, the chapter discusses the ‘verticalization’ of the international legal order with the affirmation in the second half of the twentieth century of the notion of jus cogens (or peremptory norms) and the effects this has (or might have) within international law and in its relationships with municipal laws.
Chapter
This chapter begins with a discussion of the evolution of the international law of state immunity. It then reviews the modalities of granting immunity, attachment and seizure in execution, and state immunity and human rights.
Chapter
International law has remained imprecise with respect to the scope and consequences of serious, systemic illegality, but there have been developments that have made collective action under law possible. The chapter reviews the objective consequences of illegal acts, covering peremptory norms (ius cogens), the obligation not to recognize a situation as lawful, and the obligation of putting an end to an unlawful situation.
Chapter
Disputes concerning title to land territory, including islands, and over the precise determination of boundaries are regularly the subject of international proceedings. While the occupation of territory not belonging to any state (terra nullius) is no longer a live issue, issues concerning such occupation in the past may still arise. This chapter discusses the following, the ‘modes’ of acquisition, displacement of title, territorial disputes, and territorial sovereignty and peremptory norms.
