The Application of the Most-Favoured-Nation Clause to the Dispute Settlement Provisions of Bilateral Investment Treaties: Domesticating the “Trojan Horse”

Contracting states bring a ‘Trojan Horse’ into the city when providing for most-favourednation clauses (MFN clause) in bilateral investment treaties (BIT). This affects the general equilibrium of the treaties, as recent case law from investment arbitration tribunals illustrates. In these cases the controversial issue is the applicability of the MFN clause to the dispute settlement provisions of the BITs. Arbitration practice and mainstream literature so far have focussed on the specific nature of the dispute settlement mechanism, asking whether the MFN clause should cover it or not. This article analyses the arguments put forward so far on this issue, and argues that by reason of the ‘ effet utile ’ the MFN clause always covers the dispute settlement mechanism, unless the opposite intention of the Contracting states can be demonstrated. Furthermore, this article considers that the prevailing focus on the entire mechanism is misleading. The main issue is in fact the scope of application of the MFN clause to the individual provisions on dispute settlement. Underlying this issue there is the tension between the MFN clause and the other provisions of BITs, whatever their procedural or substantive nature. This tension puts into question the rationality of providing for MFN clauses in bilateral investment treaties. But once such a clause is already adopted, this article suggests that the way to domesticate this ‘Trojan Horse’ is to substitute conditional MFN clauses for the unconditional MFN clauses presently provided for in BITs