While it's still thankfully impossible to firestorm an entire country, technological advancements in the 80 years that have passed since 1940s make it possible

While it's still thankfully impossible to firestorm an entire country, technological advancements in the 80 years that have passed since 1940s make it possible to inflict much greater damage using non-nuclear arms. If nukes deter countries from entering a war where such "conventional" power can be unleashed, then the (very real but nevertheless remote) threat of nuclear Armageddon is saving millions of lives by reducing much shorter odds of "conventional" regional/world wars. I always think about the millions currently living in India and Pakistan who would no longer be alive if not for nukes. It is also a significant deterrent in a conflict between China and India, two nations of 1+ billion people. Consequences of such a full-scale conflict would indeed be just short of nuclear Armageddon.