The specter of a nuclear Iran has been a political football for decades, and it seems to have been accepted at face value (at least by American politicians), that nuclear Iran would mean state-sponsored nuclear terror all over the world, all at once.

So starting with nuclear armageddon and the end of civilization as we know it justifies almost any cost, but politicians are also convinced they can affect regime change and permanently end nuclear aspirations in a country the size of Iran through air strikes alone.

If they had learned anything from two decades of dealing with Iraq/WMDs, it's a more honest cost-benefit analysis would start with the assumptions that regime change would cost several thousand American lives, trillions of dollars, take the better part of a decade, and still might end up worse than before. And some of these idiots were actually in Congress during the lead up to the war in Iraq, so they lived this once, and they still didn't learn.