Iran has long asserted that it can shut down the Strait of Hormuz. While the strait can't be "closed" in the traditional sense - like shutting a road - Iran could attempt to make the waterway too dangerous for commercial passage, effectively disrupting global shipping.

Pentagon officials are trying to prepare for all of the ways Iran could retaliate, as President Trump hints at what he might do.

Despite Iran's repeated threats to close the Strait of Hormuz, a vital waterway for global oil and gas transit, it has never followed through due to strategic and economic costs. Analysts believe the oil markets are well-supplied,