The EU: Unifying or fragmenting force in international law?

In this chapter, I focus on the interaction between the Court of Justice of the European Union (‘CJEU’) and the International Court of Justice (‘ICJ’), which is the principal judicial organ of the United Nations and a symbol of general international law. I consider whether the European Union is a unifying or fragmenting source in international law by focusing on the case law of its judicial branch. Fragmentation is not merely a matter of having different interpretations.2 ‘Genuine fragmentation’ occurs where judicial decisions give rise to conflicting developments in the law that are either unconscious due to lack of awareness of other courts’ decisions or are a conscious departure from existing case law. Cases of genuine fragmentation are rare in standing courts with public decisions. Greater risk of fragmentation occurs in ad hoc arbitral tribunals, which may not have public decisions. ‘Apparent fragmentation’ arises where judicial decisions have variations due to contextual factors and therefore appear to be conflicting, although through clarification and interpretation the underlying legal reasoning can be resolved and rendered compatible. It occurs most commonly where judges are interpreting different legal instruments on the same legal issue. In international law, the aim is not to have uniformity, but rather to achieve unification or integration so that similar factual scenarios and legal issues are treated in a consistent manner and any disparity in treatment is explained and justified. The desired outcome is harmony and compatibility, with allowances