No 'smack-down' here; our interests are aligned here (most likely on several levels). Israel has an interest to enforce the blockade of Gaza, the U.S. wants to show muscle against Iran (and that suits Israel too - given Achmedinnerjackets propensity to spew diatribes of wiping Israel off the face of the Earth).
Who knows, perhaps the allied flotilla has nothing to do with anything, and they're merely on a humanitarian supply mission to forces combatting the Somalian jolly rogers. Or they're on an escort mission for the Israeli's delivering a pizza to somebody in Oman and the Iranian flotilla merely gets in their way. Hey it could happen, didn't the Boy King order pizza from out of state and flown in on AF1?
I think that Israel has told the US it is an either-or proposition: Either the US acts with convenional military means, which we have more of and more access to, or they will act more decisively, meaning exercising the nuclear option, which they have already positioned in the Persian Gulf...nuclear-tipped missles launched from Israeli submarines in the Gulf.
That would be a smack-down for an inept and inexperienced Obama and real leadership, which we don’t have in the White House, but Israel has in Netanyahu.