Relationship of international law and municipal law — Recognition and enforcement of foreign laws — Expropriation legislation allegedly contrary to public international law — Whether entitled to recognition in Italian courts — Public policy — Act of State doctrine — Whether Italian courts entitled to question compatibility of expropriation legislation with international law — “Pursuit actions” — Ownership of oil extracted from area of concession after expropriation of concession

Expropriation — Compensation — Lack of effective compensation — Whether rendering expropriation unlawful — Effect of unlawful expropriation — Whether a nullity — Whether ownership of expropriated property affected — Oil concession — Ownership of oil extracted from concession area after expropriation of concession — The law of Italy