State immunity — Attachment and execution — Criteria for determining which assets immune from execution — Assets designated for non-sovereign tasks — Civil aircraft owned by foreign State airline — Whether liable to attachment to secure payment of debt owed by State corporation — Principles of customary international law governing immunity of assets of foreign State from enforcement jurisdiction in State of forum — Assets used for exclusively commercial purposes — Requirement of ministerial authorization for execution — Italian Law No 1263 of 1926

Sources of international law — Judicial decisions — Decision of Federal German Constitutional Court as evidence of customary international law

State responsibility — For debts — State corporations — Whether endowed with independent legal personality — Whether such corporations may be held liable for each other’s debts — The law of Italy