State Control Over Interpretation of Investment Treaties

Under international law, states have the right to use interpretive tools to clarify provisions in treaties to which they are signatories. Yet, in the context of international investment treaties, they have not generally been active in asserting their interpretive power over their treaties, with the exception of disputing respondent states during an ISDS proceeding and a handful of states under particular treaties; and investment tribunals have generally disregarded or undervalued state party interpretations of their treaties, especially those proffered by disputing respondent states. This has given tribunals freer rein to assert new legal norms in investment law, and expand state obligations and investor protections, in ways contrary to treaty parties’ intentions or expectations. As a result, tribunals have produced decisions that are not only incorrect, but unjustifiably inconsistent, and the system, as a whole, is unpredictable and incoherent.

CCSI researches tools that states can and do use to help influence how investment treaties are interpreted and applied. If states are able to exercise these powers more effectively, the treaties may be more likely to advance their policy goals. We also examine limitations to the use and effectiveness of these tools. For instance, there exists a power differential between states that are frequently at the receiving end of ISDS claims, i.e. capital-importing states, and those whose investors are bringing these claims, i.e. capital-exporting states. These two groups of states do not, for the most part, overlap. This means that some states are systematically sidelined in investment law making and shaping, which has resulted in the asymmetrical way that the law is developing. Those disproportionately affected by such overreach are capital importing states, which are left relatively voiceless under the current system. We explore possible reforms to investment treaties and dispute settlement mechanisms that can give states a greater role in influencing their treaties’ interpretation, and seek to be more inclusive of all state parties in the development of international investment law.

Relevant work includes: