This whole house of cards we call "relative" Middle East peace (and I use that term very lightly considering what is happening in Iraq, Lebanon, and the usual Israeli/Palestinian eye-for-an-eye mentality) is built on the premise that, given their historical dominance over their vastly more populated enemies, no one wants to engage Israel alone. But if Iran somehow gets the means to deliver a nuclear weapon to Israel (which isn't that ridiculous at the rate we're headed -- everybody remember the Scuds Saddam fired into Israel during the first Gulf War?), then all hell will break loose.
Iran needs to be stopped, and I hope we do it rather than Israel. The Muslim world will think twice against taking on the U.S. rather than their scriptural and historical (and decidedly smaller, closer, and less populated) enemy.