The United States military last week extended its blockade on vessels coming in and out of Iranian ports to the waters of the wider world, declaring that it would pursue any ship aiding Iran, regardless of location on the high seas or flag.<\/p>\n
The U.S. \u201cwill actively pursue any Iranian-flagged vessel or any vessel attempting to provide material support to Iran,\u201d Gen. Dan Caine, chairman of the Joint Chiefs of Staff, said<\/a> Thursday, noting that the American troops beyond the Middle East will engage in operations to thwart Iranian shipping.<\/p>\n The extension of the blockade comes as the economically vital Strait of Hormuz remains all but closed to commercial traffic and the two-week cease-fire between the United States and Iran nears an end. The move aligns longstanding American economic policies targeting Iran with the current military campaign against it, maritime and military law experts say.<\/p>\n But it raises a host of legal and practical questions.<\/p>\n \u201cWar is a messy thing not just on the combat side but under national and international law,\u201d said James R. Holmes, chair of maritime strategy at the Naval War College.<\/p>\n \u201cFrom a legal standpoint, a blockade is an act of war, so the blockade probably is legal to the extent Operation Epic Fury is,\u201d he said using the name of the U.S. military campaign against Iran.<\/p>\n Since Congress has not declared war against Iran, no formal state of war exists between the United States and the Islamic Republic. But Mr. Holmes noted that \u201cundeclared wars are more the rule than the exception in U.S. history,\u201d with joint resolutions of Congress, United Nations Security Council resolutions and NATO decisions invoked to justify fighting.<\/p>\n \u201cThis campaign may be more unilateral than most, but it is not without precedent,\u201d he said.<\/p>\n Under international law, the legality of the blockade is \u201cmore ambiguous,\u201d said Jennifer Kavanagh, a senior fellow and director of military analysis at Defense Priorities, a foreign policy think tank in Washington.<\/p>\n A state-organized rally in support of the supreme leader Mojtaba Khamenei in Tehran on Friday.Credit…Arash Khamooshi for The New York Times<\/p>\n