I had left it at "apparently MAD has worked thus far", not getting into the almost didn't. It still might end us. Also, think of all the past plausible/likely

I had left it at "apparently MAD has worked thus far", not getting into the almost didn't. It still might end us. Also, think of all the past plausible/likely bad scenarios that MAD averted, such as involving the Soviets. I sometimes joke about a utopian future of humanity, all peace and love, for thousands of years... until we encounter malevolent space aliens. Humanity had lost the ability to even reason about such a conflict, unable to imagine many options. Fortunately, humanity had maintained the cryogenic suspension of Kissinger and other historical figures capable of cold-blooded ruthlessness. And there was a Thaw button. (In some versions of the story, as soon as the anti-dream team wakes up and starts talking, we decide they're even worse than the space aliens.)