In the practice of modern international law, disputes as to the meaning of specific treaty provisions are a frequent occurrence. It is the assumption underlying any such dispute that in a process of interpretation a distinction has to be made between the legally correct and incorrect interpretation result. The legal correctness of an interpretation result is determined by reference to the relevant international law, as reflected in the 1969 Vienna Convention on the Law of Treaties (VCLT), Articles 31-33. The result of an interpretation process is correct when it can be successfully defended as being in accordance with the provisions of VCLT Articles 31-33. The result is incorrect when it cannot be so defended.

Traditionally, the substance of Articles 31-33 has been described by reference to the various means of interpretation enumerated in said provisions, and little more than that. As argued in this book, more detail is required. On closer inspection, not only does the Vienna Convention provide information on the interpretation data (or means of interpretation) to be used by appliers when interpreting a treaty provision. It also instructs the appliers how, by using each datum, they shall argue to arrive at a conclusion about the meaning of the interpreted provision; and, to some extent, it determines the weight that different data of interpretation shall be afforded when appliers discover that, depending on the specific datum they bring to bear on the interpretation process, the conclusion arrived at will be different. Hence, the regime laid down in VCLT Articles 31-33 will have to be described as a system of rules.

This book investigates the contents and structure of this system. By importing knowledge from linguistics, and pragmatics in particular, a model is established giving representation to the concept of a rule of interpretation. Drawing on this model, the book then proceeds to reconstruct the contents of thevarious rules of interpretation. To facilitate reference, the conclusions suggest a list of 44 rules, all of which can be invoked by appliers citing VCLT Articles 31-33.

Zusammenfassung
1 PURPOSE AND TOPIC We live in the age of treaties. Increasingly, bilateral and multilateral written agreements are used for the creation of new international legal standards. For political reasons, states are decreasingly less willing to rely upon customary international law for the regulation of legal matters. New technology and growing international exchange have established the need for an ever more precise and flexible international law a need not satisfactorily met by customary law. In many fields of activity, we can seriously question whether the creation of a rule of custom is at all possible. Considering also that the number of states capable of drafting and concluding treaties seems to be growing, it is not surprising that treaties are concluded far more frequently than ever before. In several ways this is a development that should be met with approval. By entering into written agreements, states avoid the difficulties inherent in customary international law. At the same time, the increasing number of treaties should also be causing concern. The more treaties that are concluded, the more treaties that will have to be applied; and the more treaties that are applied, the more often the question will arise: To what extent, and under what specific conditions, should such an application occur? Naturally, this includes the question of how treaties should be interpreted.

Inhalt
The Rule Of Interpretation.- Using Conventional Language (The Ordinary Meaning).- Using the Context: The Text of a Treaty.- Using the Context: The Elements Set Out in VCLT Article 31 § 2(A) AND (B).- Using The Context: The Elements Set Out in VCLT Article 31 § 3.- Using the Object and Purpose.- Using the Supplementary Means of Interpretation.- Using Supplementary Means of Interpretation (Cont'd).- The Relationships Between Different Means of Interpretation.- The Special Rule Regarding the Interpretation of Treaties Authenticated In Two Or More Languages.- Reflecting on the Outcome: International Law on a Scale Between Radical Legal Skepticism And The One-Right-Answer Thesis.