What is the restrictive theory of sovereign immunity?
A. Under the U.S. legal system, however, the scope of a foreign state”s immunity is determined by judicial, rather than executive, authorities. A party to a lawsuit, including a foreign state or its agency or instrumentality, is required to present defenses such as sovereign immunity directly to the court in which the case is pending. The immunity of a State from the jurisdiction of the courts of another State is an undisputed principle of customary international law. Until the twentieth century, sovereign immunity from the jurisdiction of foreign courts seemed to have no exceptions. However, as governments increasingly engaged in state-trading and various commercial activities, it was urged that the immunity of States engaged in such activities was not required by international law, and that it was undesirable: Immunity deprived private parties that dealt with a state of their judicial remedies, and gave states an unfair advantage in competition with private commercial enterprise. Th
