Interpretation of the United Nations Convention on Contracts for the International Sale of Goods (CISG) according to principles of international law : a reply

The successful acceptance and application of international uniform law instruments such as the CISG depends on outcomes, which are consistent and predictable in all member states. The most important single factor to achieve uniformity and hence predictability is a uniform interpretation of laws. The CISG has recognized this and introduced article 7 into its regime. Much has been written, which intends to explain the importance and function of article 7. An argument has been advanced that the Vienna Convention on the Law of Treaties (VCLT) is also applicable in the interpretation of the CISG. Specifically Roth suggests that articles 31 to 33 of the VCLT ought to be taken into consideration when interpreting the CISG. In support of their argument both Roth and Happ contend that the rules of the VCLT represent and coincide with valid customary international law. In addition the authors suggest that very few attempts have been made to explain or develop a methodology or methodological reasoning. Such an argument is given weight if article 31 of the VCLT is considered. The proposition presented by the above authors needs to be viewed critically. There is no debate that the VCLT has a relationship with the CISG. The question is how far and to what extent does the VCLT influence the interpretation of the CISG