Trump is very reluctant to commit the US to an act of war. He is unconvinced that our bunker-buster MOABs can successfully penetrate Iran’s nuclear Fordo mountain stronghold. For the moment, he is playing for time, probably hoping that Israel alone can “finish the job” (de-nuke Iran) somehow without US intervention. There is even some reasonable hope that Iran’s mullahocracy can be tossed out, at best, by the Iranians themselves.