IV.  APPLICATION OF INTERNATIONAL HUMAN RIGHTS LAW AND INTERNATIONAL HUMANITARIAN LAW BY THE UNITED NATIONS CONCLUSION As indicated throughout this study, international human rights law and international humanitarian law are bodies of law in permanent evolution. Warfare is a phenomenon in constant change and, thus, international human rights law and international humanitarian law are required to adjust constantly to avoid gaps in the protection they provide. Changes in the law stem essentially from the practice of the different organs that supervise compliance with the system. Jurisprudence by judicial organs, but also by treaty bodies, is a significant source of interpretation and is fundamental for the development of the system. But applying the rules correctly and, most importantly, providing adequate protection to populations at risk require a thorough understanding of how these different norms interact and how they complete and complement each other to afford the highest standard of protection possible. The discussion on their interaction is certainly part of a broader legal debate on the fragmentation and unity of international law. As a result, recent legal debates have concentrated on developing mechanisms to ensure maximum protection for the individual. For instance, in a number of cases, one body of law requires a referral to another body of law, as is the case of common article 3 of the Geneva Conventions, which uses concepts developed in more detail in human rights instruments, including in the Universal Declaration of Human Rights. Similarly, on certain occasions human rights law needs to be interpreted in the context of international humanitarian law, as done by the International Court of Justice in its advisory opinion on the Legality of the Threat or Use of Nuclear Weapons. Concerning their complementarity, both human rights law and international humanitarian law inform each other in a number of ways. In the context of the Human Rights Council’s discussions on this subject, different experts have highlighted that in certain complex situations some type of test may be necessary to assess the most adequate legal framework to be applied in a particular situation. 117