Progress and Regress in the Interpretation of the Concept of Essential Security Interests in International and Regional Courts

Abstract This article explores the concept of ‘essential security interests’ ( esi ) within the framework of international and regional law, specifically focusing on its historical evolution and current interpretations. The esi exception, which allows states to prioritize their security concerns over international obligations, has gained increased relevance since the turn of the millennium. This study provides a detailed analysis of how the International Court of Justice ( icj ) and the European Court of Justice ( ecj ) interpret esi clauses, highlighting the convergence and divergence between international and regional jurisprudence. By examining both self-judging and non-self-judging esi clauses, the article assesses their reviewability and the implications for legal consistency and state sovereignty. The analysis aims to clarify the practical application of esi exceptions and offer insights into potential areas for improvement in their judicial review.