There would be a political fallout anyway as Israelis start whining and moaning “The IDF is meant to protect us!” Iran has to attack, and decisively, on a major scale to [et those tinpot far king Zionists back in their box.
If the US intervenes they will lose ALL their bases in the Middle East including Diego Garcia – very important to carpet bomb the entire complex – major SIGINT and B1 bombers stationed there.
ps. Of course the Yanks will lose whatever naval assets they have in the Persian Gulf and the very large base in Qatar.
“….fire all your guns at once and explode into space….”