I mean he can do that, but that's not going to magically open the strait. Iran effectively has unlimited resources compared to whatever the US navy can bring to bear. They're on land, and fighting on their home turf. The US has a fundamental logistical disadvantage here, and there's no way around it. The US is no physically capable of opening the strait.

But, let's for the sake of argument assume that the US could magically open up Hormuz. Iran can simply destroy the rest of oil and gas infrastructure in the gulf in response. So, there's going to be nothing to ship at that point. They've already demonstrated their ability to do exactly that. They hold all the cards here.

Right, the entire point of the petrodollar is to perpetuate US hegemony, and that's precisely why the US is fucked now. As long as Iran controls the strait, they control what currency a huge chunk of oil will be traded in. Meanwhile Russia, which is the other major oil exporter, is already trading outside the dollar. On top of that, I expect that many countries will start getting serious about renewables out of sheer necessity. Even if the war stopped tomorrow, it's going to take years to rebuild the infrastructure that's been already destroyed. This isn't a short term shock countries can just ride out. So, we'll see more oil traded outside the dollar, and less demand for oil going forward. This is basically the worst possible outcome for the US.

Whatever the US agrees with OPEC is completely and utterly irrelevant here.