조약 해석에서 문맥과 함께 참작되어야 하는 추후합의와 추후관행의 의미: ILC의 작업 내용을 예시적으로 WTO협정의 해석에 적용

The Vienna Convention on the Law of Treaties of 1969 provides for the general rule of interpretation in Article 31. Paragraphs 1 through 3 of the article make up 'a single combined operation' of interpretation. Among them, paragraph 3 refers to the three interpretative elements or means of interpretation to be taken into account together with the context. Among the three interpretative elements, this article looks into subsequent agreement under sub-paragraph (a) and subsequent practice under sub-paragraph (b). The two interpretative elements suggests that "subsequent developments" made after the conclusion of a treaty have bearings on its interpretation. As time goes by, circumstances surrounding the treaty and the international law itself undergo changes while the text of the treaty stay fixed. In order for the agreement of the State parties as established by the treaty remain meaningful amid such changes, the treaty should be able to adapt to such subsequent developments. The International Law Commission of the United Nations has recently adopted provisionally five(5) draft conclusions and their commentaries on the topic of "Subsequent agreements and subsequent practice in relation to the interpretation of treaties". This work suggests clearer guidelines on issues including the general rule and means of treaty interpretation(Conclusion 1), subsequent agreements and subsequent practice as authentic means of interpretation(Conclusion 2), interpretation of treaty terms as capable of evolving over time(Conclusion 3), definition of subsequent agreement and subsequent practice(Conclusion 4) and attribution of subsequent practice(Conclusion 5). The purpose of this article is to analyse the significance of the tentative conclusions from ILC's recent work on the interpretation of the WTO Agreements. With this purpose, the article reviews and analyses the provisional conclusions of the ILC's recent work(Part II) and then examines subsequent agreement and subsequent practice to be taken into account for interpreting the WTO Agreement as well as other related interpretative elements(Part III). In Part II, analysis focuses on (i) the finding that subsequent agreement and subsequent practice are authentic means of interpretation, and that the word "authentic" refers to the common intention of the parties, (ii) the definition and requirement of subsequent agreement, (iii) the definition and requirement of subsequent practice, especially that subsequent practice consists of conducts attributable to states, and (iv) the relationship between the subsequent practice attributable to states and the practice of international actors other than states such as international organizations and non-governmental organizations that have been developed after the conclusion of the treaty being interpreted and that are relevant for the interpretation of that treaty. Based on this analysis, Part III deals with (i) the authoritative interpretation adopted by the Ministerial Conference or the General Council under Article IX:3 of the WTO Agreement, (ii) the subsequent practice attributable to the WTO member states, (iii) the decisions, recommendations and other instruments adopted or made by the organs of the WTO.