There are a lot of things short of massive nuclear attack that threaten the existance of the country. The British burned the White House in the War of 1812 without nuclear weapons.
But that is beside the point.
The point was that people were advocating the use of torture to prevent the killing of innocent people, rather than for the preservation of the nation. I was just pointing out that if we go down that road, there is going to be a heck of a lot of torturing going on.
Please note that this response does not presuppose that waterboarding is torture.