Iran would have already attempted that if it believed that it was capable of doing it without devastating consequences.
If Iran follows through with this threat, we better make sure we don’t arrive on the scene with plywood models of aircraft carriers.
Isn’t that what they want anyway?
We haven't really done very well with our containment policy with respect to Iran, largely due to having people in charge in the State Department for the last eight years who are either too stupid to understand it or too partisan and self-aggrandizing to make it work, but Iran has cooperated with it anyway by impoverishing their country in order to export revolution and produce superweapons under whose umbrella they may sustain the effort. We couldn't cripple them anywhere nearly as effectively as they've managed to cripple themselves.
Without turning this into a grand geopolitical strategy disquisition, it appears that a similar amount of damage has been done to Saudi Arabia as well, and for the same reason. The serpent has been pinned to the ground but it's still capable of killing a lot of people in the thrashing. A further decrease in the price of oil promises to slowly dry up the funds of terroristic Islam. Removing China as an Iranian customer would be a grievous blow, and Trump is the sort of a President who might just pull it off. After that it's likely to be Venezuela redux. I wouldn't shed a tear.