In the context of growing concerns about the ambiguity of the Fair and Equitable Treatment Standard, this book seeks to find solutions towards the lucidity of the legal standard and accordingly improve the stability and predictability in the application of the legal provision in international investment arbitration. Especially, in addressing the contemporary phenomenon in international investment law where the host states' sovereign freedom to regulate public interests and human rights has been irrationally challenged and forfeited for foreign investors' private interests, the book also attempts to address the inequilibrium between the foreign investor's rights on the one hand, and the public interests of the citizens in the host state, on the other.