Assuming we have 100% surveillance we will have a minute to respond to a launched barrage of Russian missiles that have a time of flight of 5 minutes or more.
It takes one of our land based missiles 4 minutes to clear the hatch after the button has need pushed.
The problem there is who has the authority to make the call that must be made instantaneously to respond in time .?
Whoever the Duty Officer in charge happens to be working grave yard shift that night..would be North America's last hope to see to it that our land based missiles get launched in time.
WE MUST HAVE a contingency plan like this that bypasses the President and even our highest ranking military commanders who will all be sound asleep.