Is he trying to pressure Europe into a joint action on Iran? Or in their calculus hurting China and Iran remains viable despite the blowback in the US? We don't have the whole picture, of course, but right now this only makes sense if to confuse your enemy you must shoot yourself in the foot first while singing Kumbaya.

It’s to make it so the strait is closed for everyone if it is closed for some. This hurts Iran’s already weak economy significantly but also its allies like China, especially if they’re shipping arms by sea.