© 2017

Treaty Interpretation Under the Vienna Convention on the Law of Treaties

A New Round of Codification


Table of contents

  1. Front Matter
    Pages i-xix
  2. The Setting

  3. Existing Issues to Be Subject to Codified Rules

About this book


This book is devoted to an idea of a second round of codification of certain new rules for treaty interpretation. Currently, treaty interpretation is guided by Articles 31 through 33 of the Vienna Convention on the Law of Treaties (VCLT). The fundamental rule is that a treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose. These rules lay the foundation for treaty interpretation. They represent the first round of codification of the contents of some previous customary international law rules. The book argues that the current rules are overly simplified. After almost fifty years of codification of the VCLT, the codified text in it is practically insufficient in addressing some traditional treaty interpretation issues (such as the interpretation involving time factors or technology development) and in coping with some new development of international law (such as the diversification and fragmentation of international treaties) and new challenges (such as the need of coordination between different treaties and the need of introducing external values, including human rights, into a treaty through treaty interpretation process). The book further argues that there is a need to have a second round of codification so as to incorporate new rules into the VCLT to be followed by treaty interpreters to make treaty interpretation more consistent and transparent, and more in line with the shared value of international community. The book proposes the contents of certain new rules to be considered as the new codified rules for treaty interpretation.


Treaty interpretation VCLT (Vienna Convention on the Law of Treaties) Ordinary meaning Textual interpretation Contextual interpretation Object-and-purpose Constitutional interpretation Statutory interpretation Contractual interpretation Codification Contemporaneous interpretation Evolutive interpretation Teleological interpretation Fragmentation of international treaties Human rights

Authors and affiliations

  1. 1.Constitutional Court of TaiwanTaipeiTaiwan

About the authors

Chang-fa Lo has been Justice of the Constitutional Court of the ROC (Taiwan) since October 2011. Prior to his current judicial position, he was the Chair Professor and Lifetime Distinguished Professor at National Taiwan University (NTU); Dean of NTU College of Law; Director of Asian Center for WTO and International Health Law and Policy of NTU College of Law (ACWH); Director of Center for Ethics, Law and Society in Biomedicine and Technology of NTU; Commissioner of Taiwan’s Fair Trade Commission; Commissioner of Taiwan’s International Trade Commission; and legal advisor for Taiwan’s GATT/WTO accession negotiations. In his capacity as the Director of ACWH, Professor Lo launched two English journals, namely, the Asian Journal of WTO and International Health Law and Policy and the Contemporary Asia Arbitration Journal (CAA) in 2006 and 2008, respectively. In his tenure as Dean of NTU College of Law, he also launched an English journal, the NTU Law Review. Prior to his teaching career, he practiced law in Taipei. He received his SJD degree from Harvard University Law School in 1989. He was appointed by the WTO as a panelist for DS332      Brazil—Measures Affecting Imports of Retreaded Tyre in 2006, DS468 Ukraine—Definitive Safeguard Measures on Certain Passenger Cars in 2014, and as a member of the Permanent Group of Experts under the SCM Agreement of WTO in 2008. He is also the chairman of the Asia WTO Research Network (AWRN) since 2013. He is the author of 13 books (including the current one) and the editor of 6 books, and has authored about 100 journal papers and book chapters.


Bibliographic information