> Nothing has fundamentally changed with respect to American power
Yes, actually - Iran is charging tolls and was not doing that before. This is in the face of an American naval blockade right in their neighborhood. That is an affront to power, at least for the moment.
The China point is really immaterial to the instant issue of the Strait, but even there China is very obviously growing more aggressive (cf the recent trip of the Taiwanese president where he had to sneak out of his nation).
> The United States casually walked in and bombed the hell out of Iran's military and killed its leaders.
Yes, but now the Strait transit is being dictated by the new rulers. We can keep killing them but the issue is that we are no longer in control of a situation that we used to be in control of. That's why the paper tiger comparison is apt—for all our bombs, this isn't in our hands.
> there's basically nothing I can do about it except to bomb defenseless oil tankers.
Iran has bombed over a dozen US installations, probably the greatest damage to US military installations in recent memory, if ever. This includes destroying equipment that's worth > $700 M. The oil tankers are kind of a distraction when they can clearly damage all of our allies' infrastructure despite being decapitated by the first strikes.
> In order to be the guarantor of the seas you have to take actions like the on in Iran.
The whole point of this is we cannot guarantee passage in the Strait. I don't think that will over go back to how it was.
> By the way, why is the US the one that has to do this?
We don't and because of this current issue, nobody will be able to do it until our next world war establishes a new, single hegemon. It was convenient while it lasted because it allowed stability for our post-war economy.