undeRGRond it will still with time radiate the under ground water and by the time they do one we will hit them hard. Also in no way would that end the U. S. ronym is talking about a total nuclear hit to the U. S. which will not happen since we will do the same back to them. That would be the end of man.
A one city maybe but we will hit back. I still do not see that as a great hit. An EMP or a large Bio attack yes. Harder to track down who did it.