International law — Relation to Municipal law — Whether courts will examine validity under international law of public act of foreign sovereign committed within own territory expropriating foreign property without adequate compensation — Competence of municipal courts to determine and apply international law Nature of customary international law standard governing State's responsibility for taking of foreign property without adequate compensation — Act of State doctrine — Nature of and policies underlying — Applicability of doctrine when foreign State's acts alleged to violate customary international law — International law as understood by courts in United States — The law of the United States of America.

Jurisdiction — Territorial — Expropriation of alien property — Expropriation by Cuba of sugar properties within Cuba indirectly owned by United States residents — Challenge to validity of expropriation in United States court — Action by Cuban governmental instrumentality to recover value of such properties after alleged conversion of sugar in United States — Whether expropriation in violation of customary international law — Relevance of failure of Cuba to pay adequate compensation — Relevance of retaliatory purpose of expropriation and discriminatory application to United States citizens — Nature of customary international law standard governing State's responsibility for taking of foreign property without adequate compensation — Application of Act of State doctrine in United States courts — International law as understood by courts in United States — The law of the United States of America.

Recognition of acts of foreign States and Governments — Expropriation of foreign-owned property situate within expropriating State — Expropriation by Cuba of sugar properties indirectly owned by United States residents — Suit by Cuban governmental instrumentality in United States Court to recover value of properties after alleged conversion of sugar in United States — Whether Court can examine validity of expropriation to determine whether instrumentality acquired title to sugar properties — Act of State doctrine — Nature of and policies underlying — Applicability of doctrine when foreign State's acts alleged to violate customary international law — Nature of customary international standard governing State's responsibility for taking of foreign property without adequate compensation — Whether recognized foreign Government may resort to United States courts — International law as understood by courts in United States — The law of the United States of America.