This happened:
EMP attack
I have been thinking about something similar to this for a little while, primarily concerned with a feasable response from the US if attacked with a single nuclear weapon. My conclusions to date have been that a nuclear war with another superpower would not be winnable, but we damn sure could win one with Iran.
Considering the prospects of having the single nuke used on us in the above manner, I'm not sure I would be itching to have that fight.
If this happened, the only purely logical response would be retaliation on a scale that would put everybody else in the world in the same boat as we were. That would be the only way I could forsee stopping the armies that would almost certainly be deployed to carve up the continental US.
Thoughts/Comments/Discussion?