OK...I'm late to this show...but I'll give it a try. It would not stop us cold in our tracks. The United States does not cede to the demands of terrorists...we may have gone way too PC in alot of other other areas of American life, but not in this situation. A likely response would not be pretty. In the event of a nuke detonation, this country would be a police state overnight. I'm thinking WWII-Japanese-style interment camps for all people of Arabic descent and/or close assoiciation with Arabic families, strict curfews, military/police/posse roundups of suspected terrorists, as well as military on the mainland tracking all the "promise of more" nukes that may be out there. I'm also thinking that we would quickly be in the process of playing the nuclear blackmail card with all other known terrorist/terrorist supporting states; as well as putting boots on the shores of said states and specOps guys taking out known terrorist facilities abroad and without warning.
There's NO WAY we would give in.