Foreign sovereign — Act of foreign State — Principle of English law — Scope and extent — Whether applicable to commercial acts — Whether nature or purpose of act decisive — Whether defence of act of State capable of waiver — Act of State not applicable to acts of foreign State performed outside its territory — Relationship of English doctrine of act of State to United States doctrine — Relationship of act of State doctrine to sovereign immunity

Foreign legislation — Penal and discriminatory — Recognition by English courts — Public policy — Conduct of foreign relations — Role of the courts and the Executive

Contract — Sale of sugar — Seller a Cuban State enterprise — Separate character — Relations between Republic of Chile and Republic of Cuba — Effect of coup d’état in Chile — Effect of Cuban legislation requiring suspension of contract shipments — Frustration — Whether State enterprise entitled to rely upon State’s actions as frustrating events — The law of England