The world did evolve with the development of nuclear weapon, but between 1945 and 1949 US was the sole nuclear power and could preemptively attack USSR as John

The world did evolve with the development of nuclear weapon, but between 1945 and 1949 US was the sole nuclear power and could preemptively attack USSR as John von Neumann proposed. That's 4 years! I suspect such window will recur with AI.