Sovereign immunity — Foreign State — Nationalization of insurance companies' assets without compensation — Action for damages against nationalizing State in United States courts — Whether nationalizing State entitled to sovereign immunity — Whether case concerning commercial activities — Waiver — Treaty of Amity, Economic Relations and Consular Rights, 1955, between United States and Iran — Foreign Sovereign Immunities Act 1976 — Whether act of State doctrine applicable

State responsibility — For taking of, or interference with, property — Applicable principles of international law — Whether duty to pay prompt, adequate and effective compensation — Local remedies rule — Application when attempt to exhaust local remedies would be futile

International law in general — Relation to municipal law — Treaties — Self-executing treaties — When individual has right to sue in municipal court for violation of treaty or customary international law

Treaties — Operation and enforcement — Effect on third parties — Whether conferring directly enforceable rights upon individuals — The law of the United States