著者

丸山 政己

出版者

一橋大学大学院法学研究科

雑誌

一橋法学 (ISSN:13470388)

巻号頁・発行日

vol.17, no.3, pp.95-114, 2018-11-10

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The balance between dynamic evolution and legal stability or fragmentation and integration of international legal order are always challenges for multilateral treaty regimes. This is partly related to the traditional debate on the status of the constituent instrument of international organizations(IOs)―particularly of IOs' own practice―in treaty interpretation. In this regard, the ILC adopted the Draft conclusions on subsequent agreements and subsequent practice in relation to the interpretation of treaties(the Conclusions) in 2018. The Conclusions is relatively self-restraining and remains within consensualism in international law. However, there are some remarkable points: clarification of subsequent practice of not the all parties as a supplementary means under Art. 32 of the Vienna Convention on the Law of Treaties ; a broader concept of the IOs' practice(Conclusion 12- 3); and indication of controversial evolutive interpretation while revision by subsequent practice is generally excluded. An examination of the Conclusions and its commentaries suggests fundamental issues to be explored. First, while the inherent doctrine of interpretation of constituent instruments still has its rationale, we have faced increasing diversity shown by various IOs. Is it really possible of general doctrine for every IO? Second, how can the extent and conditions of de facto revision by subsequent practice be found from the perspective of global constitutionalism? Lastly, reconstructing the concept of IOs' practice including organs not composed of member states, can we pursue legal control mechanisms in IOs? The agreement of all the parties will remain pivotal unless these issues are seriously addressed.