It looks like what we all knew at day one is about to happen.
Iran have demonstrated that they hold power over the strait, and their pain tolerance is far higher than ours.
I think US Intelligence and Advisers have known that from long before "Day 1". There was an interesting interview the other day (BBC Global Story "What was the Iarn deal that Trump ripped up?") with the lead negotiator for JPOCA Ambassador Wendy Sherman who was saying how they were aware of Iran's power from closing the Strait as Iran has threatened this in the past, even undertaking preparations to mine the route. nb the interview is available for download/podcast but for me not astonishing revelations, just a lot of interesting background details about the negotiations, individuals concerned, how it was progressed, etc.
Whilst Hormuz is complete access closure, other critical Straits has been closed in recent history eg Straits of Tiran (blocking access to Isreal's port at Eilat). More recently the Houthi's have threatened to close Bab al-Mandeb Strait which would close access between the Mediterranean and Indian Ocean but also a choke point for loads of communications and fibre cables ... but there are far longer alternative routes.