From expropriation to non-expropriatory standards of treatment: towards a unified concept of an investment treaty breach

The principal objective of this thesis is to examine the scope of investment treaty protection against the host state’s interference with foreign investment, and to identify the frontiers of state responsibility under international investment agreements in light of the decline of expropriation and the rise of non-expropriatory standards of treatment, including the standard of national treatment, fair and equitable treatment and umbrella clauses. In making a foray into the stormy relationship between the protection of foreign investment and the host state’s freedom to intervene in the marketplace in the exercise of its regulatory functions, this study is embedded in the wider context of the ongoing debate about the design of the mechanism of investment protection as well as its function in practice. It is argued that the expropriation standard does not provide an adequate framework for determining investor claims against host states. The thesis puts forward a proposal to abandon expropriation and to adopt a unified standard of treatment based on the guarantees of non-discrimination, non-arbitrariness and due process of law