But most people interpreted (value of the world after nuking Russia) to be quite low because Russia would automatically launch a retaliation, and the same vice versa from Russia's perspective. So with this utility game theory predicted the Mutually Assured Destruction standoff that so far has turned out correct.
(value of Russian civilian lives) = 0
(value of the world after nuking Russia) > (value of the world where Russia takes over) * (probability of Russia taking over)
Then game theory would suggest first strike would be best solution.