The Interplay between the Legislative Power of States with Foreign Investors Legitimate Expectations

The power of States to alter their laws and regulations in a way that no harm is inflicted on foreign investor's rights, has always been one of the challenging issues under international investment law. One the one hand, the foreign investor expects that the laws and regulations of the host State remain unchanged in the course of his investment, but on the other, the efficient administration of society requires the amendment of laws and regulations based on the society's ruling circumstances. The interplay between the two above-mentioned trends, is subordinate to various factors. Hence, this article deals with the question that what role, the legitimate expectations of an investor, play with regard to the consistency of the laws and regulations of States. Applying analytical and descriptive method and by examining treaties and the awards rendered by investment arbitral tribunals, attempt is made to demonstrate that the legitimate expectations of investor may have a direct impact upon the host State's legislation discretion and entitles the investor to certain rights.