State immunity — Jurisdictional immunity — Retroactivity — Restrictive doctrine of immunity — Tate Letter, 1952 — Foreign Sovereign Immunities Act 1976 — Whether applicable to acts taking place before 1952 — Nature of State immunity — Whether foreign States having a right to immunity — Whether immunity merely a matter of comity — Property of Jewish owner seized during Second World War — Expropriation exception to immunity

Comity — State immunity — Whether immunity a matter of comity or a legal right — The law of the United States of America