States as international persons — In general — Recognition of acts of foreign States and governments — Act of State doctrine — Expropriation of property — Property located in the United States — Whether United States courts will give effect to foreign decree purporting to affect title to property in the United States — Trademark — Republic of Cuba — Decree confiscating entire assets of Cuban corporation — Effect of dissolution of the corporation under Cuban law — Title to corporation’s trademark in the United States — Whether former owners retained title — The law of the United States