국제환경법과 WTO법상 의무의 충돌 해소에 관한 연구

Resolving Conflicts of Obligations under the WTO Law and International Environmental Law －With Special Reference to the Rules of Interpretation in the 1969 Vienna Convention on the Law of Treaties－

What once appeared to be governed by 'general international law' has become the field of operation for specialist systems such as 'international economic law', 'environmental law'- each possessing their own legal principles, and autonomous institutions. This is a consequence of the fragmentation of international law. If a party were to implement an obligation under a certain law, it would be in conflict with implementing another law. This issue is called a 'conflict of obligation.' In 2006, an International Law Commission(ILC) report stated that traditional legal principles, such as lex specialis or lex posterior, can be applied to resolve the issue. Moreover, the ILC suggested the method called 'systemic integration' which stipulates that one law can be interpreted in the context of another law because international law is 'a legal system.' However, some international environmental law have no legally binding force but have normative values. This is a characteristic of 'soft law.' If an international environmental law is breached, it affects the entire international community and breaches 'obligation erga omnes.' On the other hand, World Trade Organization(WTO) laws have some tendency to exclude the other legal applications in the field of trade. However, WTO DSU Article 3.2 states that "The Members recognize that it serves … to clarify the existing provisions of those agreements in accordance with customary rules of interpretation of public international law." This has a tendency to avoid isolation from general international law. Every member of the WTO has an legal interest in implementing WTO law. In this sense, it can be said that an obligation under the WTO law is an obligation erga omnes partes. Many Multilateral Environment Agreements(MEAs) allow or prohibit the trade of certain products, commodities, plants or animals for environmental reasons. The purpose of the WTO is trade liberalization but it also focuses on environmental protection and they have some exceptional cases regarding the environment. However, there is a possibility of conflict between the MEAs and WTO rules. This paper attempts to resolve the conflict with the assumption that the WTO avoids isolation from general international law and international environmental law has the characteristics of obligations erga omnes. The suggested ex ante solution is to apply lex posterior provided in Article 30 of the Vienna Convention on the Law of Treaties(VCLT) or providing the conflict clause. This ex ante method is a rare case and normally the conflict can be resolved through ex post interpretation. The presumption against conflict is the starting point, then Article 31 and 32 of the VCLT can be applied to draw teleological interpretation. If the text of a treaty can be interpreted in two ways and if the one interpretation has an effect on the treaty and the other does not have any effect, the interpretation that does have effect in accordance with the principles of 'good faith' and the 'objectives and purposes' provided for in Article 31, is generally taken. That is called 'principle of effectiveness.' Also, 'systemic integration' can be pursued by applying Article 31.3(c) of the VCLT. Here, integration does not prioritize one segment of one law over another. However, it harmonizes the different values. It connects specialized segments and links them with universal principles. In order to utilize Article 31.3(c) which states that 'any relevant rules of international law applicable in the relations between the parties', the scope should be narrowed to the disputing party. The scope of the 'relevant rules of international law'should not be confined to the time of conclusion but expanded to its interpretation as well. An example of this attitude can be found in case law, vis-a-vis the US-Shrimp case, where the WTO Appellate Body referred to the UN Convention on the Law of the Sea, CITES, the Convention on Biological Diversity when it interpreted 'exh