It is a great privilege to contribute to this Festschrift in honor of Professor Siegfried Wiessner and his wonderful academic career and lifetime contribution to international law, whom I had the honor to learn from, both as a student and academic fellow. Soon after I had the opportunity to become Professor Wiessner’s LL.M. student, I learned his fundamental theory on Policy-Oriented Jurisprudence, which, assisted by the progressive interpretation of law, helped me develop the International Hybrid Law Concept, a legal norm extensively used these days in climate change and human mobility research and litigation. This demonstrates the fantastic influence Professor Wiessner exercises in the international law arena, and his immense impact on the expansion of law, in general. Today, I am honored to work with Professor Wiessner as an academic fellow, being one of the few who returned to his wonderful graduate program to teach as a visiting professor