Strategypage addresses the Iranian mine threat and the usefulness of mines:
Iran would probably mine the straits if sanctions, or military action, halted all Iranian oil exports. Otherwise, mining the straits would be economic suicide. If Iran tried to shut down the Straits of Hormuz, it's more likely that effort would fail and the straits would remain open for non-Iranian oil. With the loss of their oil exports, Iran would find its remaining military forces being hunted down and destroyed day after day. Not only would Iranian oil exports be halted, but so would imports. Iran depends on imports of food (over 100,000 tons a week) and gasoline to keep its economy operating.
For an Iranian mining attempt to work they would have to get the mines onto the bottom of the straits and then prevent the rest of the world from clearing those mines. That would be difficult, as will Iranian attempts to plant additional mines. Such attempts would not be impossible as Iran has small submarines and speed boats along with sailors willing to carry out suicidal missions to deliver the mines. Even that may not be sufficient as this sort of fanaticism failed against the Americans in the 1980s. While Iran has worked to overcome their shortcomings, most of the solutions appear to be publicity stunts mainly meant to make the Iranian population feel better.
The post also outlines earlier mine campaigns. That, too, should be a lesson.
As China increases its ability to project power to Taiwan in order to invade or, through credible threat of invasion, cow Taiwan into submission, we should not forget that mines would wreak havoc with Chinese attempts to move forces by sea to Taiwan.
Taiwan needs mines as much as high-tech offensive and defensive missiles. And we should make sure we can deploy mines from the air in the Taiwan Strait before our fleet can fight its way closer to Taiwan through Chinese anti-access weapons.
Mines are neither good nor evil. They are tools. Just because we expect to be on the anti-mine side with Iran doesn't mean we shouldn't use them ourselves when the circumstances justify deployment.
