Iran doesn’t need to close it down. They’re quite capable of sining a couple of tankers, which would make shipping in the Gulf uninsurable, thus achieving the same effect. It may be necessary to strike Iran, but we shouldn’t be Pollyannish about it. Things will get very messy if we do.
Iran did not sink a single oil tanker during the entire "Tanker War" from 1984-1988. Tankers took direct hits from Silkworm missiles and it was like elephants getting hit with a slingshot.
What makes you think that the Iranians are "quite capable of sining a couple of tankers" now when the Persian Gulf is crawling with U.S. airpower?
During the Tanker War, 546 commercial vessels were damaged.
The oil kept on flowing.