The book provides a sophisticated analysis of state immunity from an enforcement perspective. It covers all relevant legal techniques of enforcing an arbitral award against a sovereign state. Besides tackling the plea of state immunity through the courts, this book also covers notable non-judicial remedial measures which may aid the aggrieved investors in satisfying their claims against state parties to a dispute. These measures may be used either to enhance the effectiveness of judicial remedies or as stand-alone remedies when legal measures seem (or prove to be) ineffective. After having identified problems arising from a lack of universal agreement on state immunity and the diversity and, more dishearteningly, the inadequacy of forms of enforcement available to an aggrieved claimant, this book proposes a new approach to solve state immunity issues. The international community must work towards the setting up of a central enforcement agency, a functional model of enforcement.