- Gleider HernándezGleider HernándezProfessor of Public International Law, Katholieke Universiteit Leuven and Open Universiteit Nederland
This chapter assesses the relationship between international law and municipal law. Though international law deals primarily with inter-State relations, and municipal law addresses relationships between individuals or between individuals and the State, there are many overlapping issues on which both international and national regulation are necessary, such as the environment, trade, and human rights. Though the international legal order asserts its primacy over municipal legislation, it leaves to domestic constitutions the question of how international legal rules should be applied or enforced in municipal orders. Two conflicting doctrines define the relationship between international and municipal legal orders: dualism and monism. Dualism is usually understood as emphasizing the autonomy and distinct nature of municipal legal orders, in which the State is sovereign and supreme. Meanwhile, theories of monism conceive the relationship between international and municipal legal orders as more coherent and in fact unified, their validity deriving from one common source.