Comparative international law? The role of national courts in creating and enforcing international law

Academics, practitioners and international and national courts are increasingly seeking to identify and interpret international law by engaging in comparative analyses of various domestic court decisions. This emerging phenomenon, which I term 'comparative international law', loosely fuses international law (as a matter of substance) with comparative law (as a matter of process). However, this comparative process is seriously complicated by the ambiguous role that national court decisions play in the international law doctrine of sources, under which they provide evidence of the practice of the forum State as well as being a subsidiary means for determining international law. This article analyses these dual, and sometimes conflicting, roles of national courts and the impact of this duality on the comparative international law process.