Is the bankrupt US up to it? Economically, politically and in terms of morale? The closing of the strait is the ultimate weapon. I don't believe that the Iranians will use it against the imposition of sanctions, severe as they may be, as they have threatened. Only a military attack would warrant such a response.
If Israel attacks alone -- "the most stupid idea I ever heard of," as our former Mossad chief put it -- that will make no difference. Iran will consider it an American action, and close the strait. That's why the Obama administration put its foot down, and hand-delivered to Netanyahu and Ehud Barak an unequivocal order to abstain from any military action.
That's where we are now. No war in Iran. Just the prospect of a war in Gaza. And along comes this evil Mash'al and tries to spoil the chances of that, too.