International law and national law

Abstract

Course-focused and comprehensive, the Textbook on series provide an accessible overview of the key areas on the law curriculum. International law deals with the legal relations between sovereign states while national law deals with the legal relations of individuals within a state. However, there are cases when two legal systems overlap, such as whether British courts can invoke the principles of international law to resolve civil or criminal matters. This chapter examines the relationship between international law and national law and the issues associated with their overlap. It considers how national law affects decisions before international courts and how international law affects decisions before national courts. The chapter first looks at three theories that explain the relationship of international law and national law, namely: monism, dualism, and subject matter. It then explores international law in the national law of the United Kingdom, with an emphasis on treaties and similar international instruments, together with executive certificates and ministerial discretion.