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.
