US Naval Blockade
Law of Naval Warfare
A naval blockade is a recognized act of war under the law of naval warfare, distinct from peacetime maritime law. Under customary international law and the 1909 Declaration of London, a lawful blockade must be declared, effective, and applied impartially to all neutral parties — it cannot single out one nation's shipping without broader declaration. The US announced on April 13, 2026, that it would blockade Iranian ports specifically, directing ships to turn back to Iran, with 21 ships already turned back.
- The US framed the blockade as applying only to ships travelling to or from Iranian ports, not as a closure of the strait itself.
- Critics argued the port-specific blockade still constituted an act of economic warfare against a third country without UN Security Council authorization.
- Iran's counter-move — reimposing strait controls — essentially matched a blockade with a blockade, creating a standoff with global economic consequences.
● Tracked since April 14, 2026 · last seen April 18, 2026 · updates as the daily brief publishes
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