Irans plans to close the Strait of Hormuz have been developed for some time.
Mines were emphasized in 2001.
Iran Readies Plan to Close Strait of Hormuz
Iran last mined the Gulf in 87-88, and damaged several ships. This was with 1915 type mines. China sold Iran EM-53 mines in the 90's. The EM-53 mines fire missles from close to the bottom of the ocean.
Strait of Hormuz
Iran hit a couple hundred ships, and seriously damaged 20 ships in the 87-88 conflict. Today, Iran's mobile missles wil do considerabley more damage. The US Navy will have little defense against missles form a hundred miles of mountains.
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