3 Validity of Blockade

The validity conditions (the London Declaration's canonical six — the exam's check-list): 1. Declaration: formally declared and established (a de facto blockade's notification defect); 2. Notification: communicated to neutral powers and to the local authorities (the vessel's entry "in ignorante" protected — the first violation excused on notice-ignorance); 3. Effectiveness: maintained by a force sufficient really to prevent access — the paper blockade's voidness (the 1856 Declaration's founding reform — the Crimean-War practice's answer); 4. Impartiality: applied equally to the ships of all neutral flags (the selective blockade's invalidity); 5. Legitimate object: against the enemy's coast (military purpose), not a starvation siege of the civilian population — the modern humanitarian overlay (the San Remo Manual's update: the starvation-prohibition; the Gaza blockade controversies' law's test-bench); 6. No bars on neutral ports/straits: the blockade may not bar access to neutral ports or international straits (the Denmark straits' classic; the modern law-of-the-sea overlay — UNCLOS's transit-passage regimes untouched). Invalidity's consequences: capture without a valid blockade = ** wrongful interference** (reparation; the prize court's release duty); the pacific blockade (without war) — no prize jurisdiction at all (the modern law's consensus: force-short-of-war against commerce unlawful under Article 2(4) — the 1962 Cuban missile crisis's "quarantine" the terminology's evasion case).