Introduction

Most investment treaties include a so-called minimal standard of treatment (MST) that requires that the host State treat foreign investors in accordance with an undefinable standard such as 'fair and equitable' treatment. Traditionally, this type of provision applied only to extreme cases of mistreatment. Arbitral tribunals under the North American Free Trade Agreement's (NAFTA) investment chapter have interpreted this provision much more broadly, however. In so doing, these tribunals have both destroyed the traditional barrier to second guessing legitimate government decisions ...