Against this backdrop, and despite the fact that historically arbitral tribunals had a more liberal approach to determining whether the economic activity constitutes an investment, a trend is discernable, according to which arbitral tribunals have applied a more restrictive approach by importing objective criteria, known as the so-called Salini test,2 to set limits on the definition of an investment under Article 25.3 The so-called Salini test has resulted in unsettled and inconsistent awards that act as sand, rather than oil, thus hampering the investment machine.

In this paper, I will take the position that arbitral tribunals applying the Salini criteria are essentially negating a defined term mutually agreed by the parties and importing their own meaning. This application is not consistent with what the founding fathers envisioned when drafting the Convention or with treaty interpretation provisions under the Vienna Convention on the Law of Treaties (hereinafter the "VCLT"). Further, the applicable treaty is the governing law as lex specialis4 between the Contracting States and there is no reason for an undefined term in the ICSID Convention to have precedence over a defined term in a consenting legal instrument.5