CHAPTER 5 Signs of a Subjective Approach to Treaty Interpretation in Investment Arbitration: A Justified Divergence from the VCLT? Julian Wyatt The mode of interpretation of all legal texts can be placed somewhere on the continuum between a subjective approach, which emphasises the intentions of the writer, and an objective approach, which emphasises the understand- ing of the reader. Public international law’s preference for an objective interpretation of treaties was consecrated with the adoption of the Vienna Convention on the Law of Treaties (VCLT) Articles 31 and 32 which relegate express mention of intention to supplementary means of interpretation and the exceptional case of special meaning. While many investment tribunals have followed the objective approach mandated by the VCLT and favoured by other international courts and tribunals, a group of relatively recent invest- ment cases addressing the vexed issue at the intersection of most-favoured- nation clauses and dispute resolution provisions has ventured off in a different direction that privileges elements of subjective treaty interpretation. In all such cases, the heed paid to the drafter’s intentions has resulted from the citation of the principle of contemporaneity, an oft misunderstood principle applicable to the interpretation of treaties through time that in fact takes no position on the subjective/objective interpretation divide. After noting this apparent re-emergence of a subjective approach to treaty inter- pretation in investment arbitration, the present chapter explores what factors may have led to such a divergence from the interpretation orthodoxy of general international law. It ultimately suggests that this may be a result of the under-recognised influence of investment arbitration counsel on invest- ment law, with many of those counsel being much more accustomed to 89 EXTRACT