A Justificatory-Analytical Examination of the Principle of Legality in Crimes and Punishments in Light of the Citation System and Jurisprudential Practice of International Criminal Law: From Disorder to Legal Order
Abstract
The contemporary international legal order increasingly relies on criminal law to protect the fundamental interests of the international community. The principle of legality in crimes and punishments (nullum crimen, nulla poena sine lege) operates as a key guarantee of individual rights and a precondition for the legitimacy of international criminal justice. This article examines the problem that, despite its formal recognition in major human rights and criminal law instruments, the scope, sources, and implementation of legality remain contested in international criminal law, particularly regarding customary norms, ad hoc tribunals, and the International Criminal Court (ICC). Its main objective is to analyze, from a justificatory-analytical perspective, how the principle of legality has been conceptualized, grounded, and applied within the treaty–customary “citation system” and the jurisprudential practice of international criminal tribunals and courts. Using a qualitative doctrinal and jurisprudential method, it analyzes human rights instruments, the statutes of international and hybrid tribunals, and leading judicial decisions. The findings show that legality is rooted in both written and customary international law, that international and hybrid tribunals have operationalized it through interpretive practice (especially regarding the legality of crimes, non-retroactivity, and the prohibition of analogy), and that the ICC Statute provides the most detailed codification of legality while still relying on international human rights standards and domestic systems under the complementarity regime. Overall, the article argues that the consolidation of the principle of legality in international criminal law is simultaneously a safeguard for individuals and a structural requirement for international peace, security, and the rule of law.