"But new wars are often different than their predecessors."

Yes, AI, but we are already vulnerable to nuclear war, with its HEMP and catastrophic climate disruption.

No, WWII was not a nuclear war. The destruction of Hiroshima and Nagasaki was, in that context, an extension of the firebombing induced firestorms which destroyed dozen of cities in Europe and Japan. (Don't believe the myth that it was the magic wand that ended the war.) A major nuclear exchange would be something of an entirely different order.