The day after a nuclear attack on America, or more likely, that night, most of the nations that are clamoring for our demise would be the targets of 21st century weaponry. And they are not nuclear. Nukes are old technology. Look at the F18 Hornet and a WWII Corsair, do you think similar progress has not been made in other areas of weapons technology? No infrastructure damage, no lasting contamination, no survivors. It will be politically unavoidable for the government to do otherwise.
I have no doubt about our ability, only our will.