State immunity — Attachment and execution — Criteria for determining which assets immune from attachment and execution — Property not specifically designated for fulfilment of sovereign functions — Ship owned by foreign State company — Whether liable to attachment to secure payment of debts guaranteed by foreign State — Principles of customary international law governing immunity of assets of foreign States from enforcement jurisdiction in forum State — Distinction between jurisdictional immunity and immunity from execution — Distinction between immunity from execution and immunity from attachment

State immunity — Attachment and execution — Requirement of ministerial authorization — Legality — Property not specifically designated for fulfilment of sovereign functions — Italian Law No 1263 of 1926 — Whether authorization requirement violating constitutional right of individuals to judicial protection — Italian Constitution, Article 24

States — Conduct of foreign relations — Foreign policy interest of executive in preserving good relations with other States — Whether justifying curtailment of constitutional right of individuals to judicial protection — Rule requiring ministerial authorization for judicial enforcement against property of foreign States in forum State — Alternatives available to executive in order to avoid damage to its foreign relations — The law of Italy