State immunity — Jurisdictional immunity — National of receiving State employed by commercial office of foreign State as secretary and administrative officer — Dismissal — Claim for reinstatement and unpaid allowances — Whether foreign State entitled to jurisdictional immunity — Restrictive theory of immunity — Scope of application to disputes concerning employment contracts — Limitation to cases where there is actual likelihood of interference with performance of sovereign functions — Types of claims involving such interference — Distinction between claims for reinstatement or damages and claims for unpaid allowances

Sources of international law — Customary international law — European Convention on State Immunity, 1972 — Whether evidence of established customary international law — Doctrine of restrictive immunity in relation to employment contracts — Application in State which has signed but not ratified the Convention — The law of Italy