China gets 45% of their oil through the Gulf. They're going to be burning up phone lines to Tehran telling them to make a deal.

The other thing are the mines themselves - the Chinese aren't going to be gung-ho about sailing their brand new pretty Navy through mine infested waters. They'd rather the US Navy do that.

I don't think they'd sail the navy through the strait. They'd escort the vessels through the blockade. The US Navy isn't going to set up their blockade in the area that's mined - they'll be seaward of that spot.

As for "burning up the phone lines" to get Tehran to cut a deal, that seems unlikely. They're vastly better off if the U.S. gets our nose pushed in by this whole affair and are far more likely to try to get oil deliveries out instead. That's why I worry about Chinese-flagged vessels being a potential solution they employ. That ramps up the stakes dramatically.

So the solution here is likely to be: blockade all tankers carrying Iranian oil, regardless of whose flag they carry. It's unlikely China will let Iran re-flag their ships because that would mean a) China taking Iran's side, openly b) China really pissing off the other Gulf states, from which they buy lots of oil.

Well, that effectively closes the straits, though. If we're not letting Iranian oil through, it's doubtful that Iran will let other oil through - or any of the other cargo that's being held up, like natural gas or helium or fertilizer. That's going to put a lot of stress on the global economy - to say nothing of those "other Gulf states," which we would like to have as allies as well.

It becomes a contest of which side is willing to suffer more punishment. Is the U.S. willing to endure rampant price increases and (perhaps) a worldwide recession bordering into a depression? Is Iran willing to endure the damage to its economy? With leadership in both countries being fairly insulated from political pressure from the people (Iran's not a democracy, Trump's not up for re-election), this could go on for quite a while...