Obama, the Chosen One, has apparently decided to offer to put Israel under the US "nuclear umbrella." That would mean that if Iran launches a nuclear attack on Israel, the US would obliterate Iran. Mutual Assured Destruction (MAD) is what Democrats like as opposed to a missile defense shield. Democrats assume that our opponents are rational human beings. That is why they think it is profitable to talk to dictators; that reasoning with them will work. MAD worked with Russians who are not suicidal. But, Iran's leaders are suicidal, at least they are willing to sacrifice their fellow citizens. Here is what Bernard Lewis, who has studied Muslim society extensively, has to say about this (I got the quote from 'Powerline'):

Bernard Lewis has observed that "Iran's leadership comprises a group of extreme fanatical Muslims who believe that their messianic times have arrived." Accordingly, for the Iranian regime, "mutually assured destruction is not a deterrent factor, but rather an inducement" because the regime's authorities believes it "can hasten the final messianic process. This is an extremely dangerous situation of which it is important to be aware."