All it takes is for one to slip through undetected to do massive damage to this country.
We See What Others Cannot
cybershafarat.com
"Russian nuclear submarine of the Borey project (according to other sources, it was an Akula project submarine), approached the US coast unnoticed. It was possible to establish the whereabouts of the nuclear submarine with up to 160 nuclear warheads on board after the sub started going back to the base. A submarine of this class is capable of destroying most of the territory of the United States of America in minutes."