nonsense
Precautionary nuclear strike to completely destroy the adversary before it
make it to strike back will left the winning side with totally life-sustaining continent.
It will be a short war.
You think people are required to be alive to launch nukes?
Living people are required TO PREVENT nukes from launching on their own... It's designed this way because of what you just suggested... The mantra was "you either launch first, or convince your enemy that you can launch retaliatory after you're dead." The problem is that in the absence of human discretion, they will launch against multiple targets, not just the aggressive nation who launched the preliminary strike.
If one country were disabled by a nuclear attack, the nukes will launch themselves at targets permanently flashed into onboard hardware. Some from unknown locations in the oceans, some from satellite orbit...
There are nuclear weapons small enough to launch from a cannon, how many nukes do you think are orbiting the Earth right now?
What you're suggesting is childish and out of touch with reality...