Does MAD Still Prevail?

The United States was never attacked with nuclear weapons during the Cold War because the Soviet Union knew that such an action would result in its extermination within a few hours. Vice versa applied as well, or as it was known, Mutually Assured Destruction.

Is that still our policy? If Iran or North Korea detonates a nuclear weapon on American soil, does America still have the cojones to respond appropriately, i.e. turn the offending nation in a lifeless radioactive wasteland for several thousand years?

Osama Bin Laden thought that the U.S. was a paper tiger, and would react from the 9/11 attacks by retreating from the world. He was wrong. Still, there is still a sense in the Arab world that America is a nation of cowards, and this perception is dangerous, as it encourages them to attack the United States.

We cannot afford for the Iranians, or anyone else, to even consider that they might survive such an attack on the United States. So I propose that the President make this statement, or something to this effect:

It is the policy of the United States, that if it suffers an attack on its homeland with weapons of mass destruction, then the offending party and its supporters will be immediately exterminated with massive nuclear retaliation.

It will give all but the most psychotic Islamo-fascist pause for thought. And although Bin Laden and company don't care if they live, the nation-states which support them do care. And we can greatly impact their decisions.