I think I remember the Iranians trying this in the 80’s, and President Reagan ordered our navy to sink their whole navy, and it was done.
1988 Operation Preying Mantis only sunk 1 FFG, 1 PTG, and 3 PBs.
Not even close to the entire navy. At that time they had 3 DDs, 4 FFGs, 11 PTGs, and about 100 PBs.
I know, I was there for it. I&W watch, CJTFME/CMEF.
Every time they hold these exercises [1-2 times a year], this claim is made. It is their way of causing a spike in oil prices - remember that oil is their economy...
It'd be too bad if a bunch of big rocks suddenly ripped out the bottoms of all of Iran's ships.
The other episode was the "tanker wars" during the Iraq-Iran war. Both sides took to attacking freighters in the Strait. The US took the side of Iraq, despite Iraq's Exocet attack on the Stark. However, when Iran attacked US-flagged tankers, the navy counter-attacked and sank a pair of Iranian cruisers.
If that whole era sounds confused and contradictory, it was. But one lesson that came out of that war is relevent today. In the 1980's Reagan made clear that any attempt by Iran to close the Strait would be seen as an act of war and dealt with accordingly. Iraq actually tried to bait Iran into closing the Strait--knowing that the US would come down decisively with both feet--but Iran was smart enough then not to take the bait. Are they as smart now as they were then? We'll see.