Thermonuclear weapons: expensive and pointless. Once a country has “enough” of them to deter an attack by a nuclear-peer via MAD, adding more is completely pointless. You only need to MAD once, currently all other planets are already sterilized. Russia, US, China already have enough in their stockpiles for a MAD situation.

Maybe a temporary return to the anxiety-ridden existential madness of the early nuclear proliferatuon age could be a good thing, as it might scare people into wishing things could go back to being more “controlled” and existentially sane.

Oh wait, what? The climate is changing and coal is cute? Never mind.