Articles 30 and 59 of the Vienna Convention on the Law of Treaties in Action: The Decisions on Jurisdiction in the Eastern Sugar and Eureko Investment Arbitrations

In a number of recent investor-state arbitrations on the basis of intra-EU bilateral investment treaties (BITs), respondent states, supported by the EU Commission, have argued that their accession to the EU has rendered existing BITs with old EU Member States obsolete. This argument is mainly based on Articles 30 and 59 of the Vienna Convention on the Law of Treaties, dealing with the effect of subsequent treaties addressing (partly) the same subject matter. This contribution discusses the treaty law implications and explains why, so far, investment tribunals have rejected the idea that BITs and the EU treaties address the same subject matter or would be so far incompatible that BITs have become obsolete.