One option stops a Nuclear War

It has been the same thing for 7 decades

I'm all in a for a defense barrier.
Even today, Nuclear weapons are the biggest deterrent for a World War.
Yes, even bigger than a barrier. Technology is created by man, it can miss.
We can still, deliver a death blow to a country, minutes after a first strike,
Otherwise, America would have been attacked a long time ago.
Total destruction, leaves the evil power monger, nothing or nobody to,
Oppress, torture and rule over, that isn't dead, sick or dying.
When does the delusional psychopath vaccine come out?