United States will not survive a nuke attack on any city
The economic disaster and shear panic that follows will not be survivable
Trying for New York or Washington --- I don't believe
they can do it. But with the Russia or China giving them
the tech; well that's another issue.
As for panic in America from a NK strike. We needn't worry.
NK would be a smoldering ruin within 30 minutes
of any attack on the USA. There would be no
worry of another attack from them.