March 1984 – "Tanker War" phase of Iran-Iraq War: Iran launched 44 attacks on foreign tankers over nine months, targeting vessels associated with Iraq or its allies, particularly in the Persian Gulf and near the Strait of Hormuz. 

July 24, 1987 – Mine attack on Bridgeton: As part of Operation Earnest Will, the re-flagged Kuwaiti tanker Bridgeton (under U.S. protection) hit an Iranian mine in the Persian Gulf, highlighting Iran’s use of naval mining to disrupt shipping. 

April 18, 1988 – Operation Praying Mantis: In retaliation for the mine strike, the U.S. launched a major operation that destroyed nearly 40% of Iran’s navy, effectively curtailing its ability to threaten the strait during that conflict. 

March 28, 1995 – Missile deployment: Iran installed anti-ship missiles on disputed Gulf islands, escalating regional tensions and raising concerns about its capacity to control or block the strait. 

December 28, 2011 – Closure threat: Iran’s first vice president publicly threatened to close the Strait of Hormuz in response to U.S. and European sanctions, particularly those targeting Iranian oil exports. 

June 2019 – Attacks on oil tankers: Iran was accused by the U.S. of attacking the Front Altair and Kokuka Courageous with limpet mines or drone strikes, though Iran denied involvement. 

April 2015 – Seizure of MV Maersk Tigris: Iranian patrol boats fired warning shots and redirected a Marshall Islands-flagged container ship into Iranian waters, asserting control over passage through the strait. 

"These actions reflect Iran’s long-standing strategy of using the Strait of Hormuz as a geopolitical lever during periods of heightened tension."