I'm pretty sure that the research showing the risk of nuclear winter being exaggerated is specifically intended to make nuclear war "thinkable" in a way it wasn't towards the end of the Cold War. It's one small part of a broader trend in elite consensus-making over the last 10 years or so. As a member of the Posadist 4th International, I approve, of course.
https://en.m.wikipedia.org/wiki/Nuclear_winter#Criticism_and...
Just like magic... if enough people stop believing in nuclear winter, then it becomes a nuclear free for all.