This article examines state immunity in a Swiss international civil procedure against foreign states, including the enforcement of such decisions. !e author argues that immunity is a procedural prerequisite for Swiss jurisdiction, determined by the nature, not the purpose of the business giving rise to the claims in question, as determined by the lex fori. !e business in question must be of a kind as could be conducted between solely private parties (acta iure gestionis). !e author argues that the requirement of a domestic nexus, as developed by the case law of the Federal Supreme Court, should be abolished. In enforcement proceedings, besides requiring an actum iure gestionis, the assets enforced against must themselves not serve sovereign purposes, as determined by the lex fori. Although the Federal Supreme Court requires a domestic nexus also in enforcement proceedings, the author considers this requirement to be incongruous with the question of immunity.