Even from the pure realpolitik perspective, I don’t understand how the cold warriors came to the conclusion that massive destabilization of a nuclear superpower

Even from the pure realpolitik perspective, I don’t understand how the cold warriors came to the conclusion that massive destabilization of a nuclear superpower was a desirable outcome. Didn’t we learn our lesson from humiliating post-Soviet Russia in the 90s? (Or Versailles-ing Germany?) Economic desperation yields aggressive strongmen and violent populations.