The Application of International Treaties in Indonesian Law: Incorporation, Transformation, and Judicial Interpretation

Ideally, the domestic application of international treaties should rest on clear criteria distinguishing states’ international obligations, domestic legal applicability, and judicial use. In practice, however, Indonesia faces uncertainty regarding the legal effects of ratification, the need for implementing legislation, and the function of judicial references to treaties. This study examines incorporation, transformation, and judicial interpretation and develops criteria for classifying treaty application within Indonesia’s legal system. It adopts a qualitative, library-based doctrinal methodology employing statutory, conceptual, and case approaches. Legal materials are examined through prescriptive analysis, grammatical and systematic interpretation, and analysis of judicial reasoning. The findings indicate that, across the selected instruments and judgments, ratification does not automatically render every treaty provision directly applicable, while implementing legislation does not necessarily establish substantive transformation. Incorporation and transformation conacern mechanisms for receiving treaty norms, whereas judicial interpretation concerns their function in legal reasoning; these mechanisms may operate concurrently. The study proposes four classification criteria: the legal basis for domestic reception, the normative sufficiency of treaty provisions, the function of implementing instruments, and judicial use. These criteria provide an analytical foundation for strengthening legal certainty.