The only cards the US has left to play are ground invasion, Nuclear strikes, and continued/elevated air campaign. Trump is more than likely too pussy for options 1&2 and Iran has proved resilient enough to withstand option 3 for as long if not longer than the Americans can sustain sorties over Iran. Also none of these options would quickly open the strait. I assume the IRGC has dug in positions with a advanced orders to continue firing until told otherwise in the event of a nuclear strike. A ground invasion would still take months/years to clear the fire bases which are closing the strait. The USA has no cards to play which can counter the closure of the strait.