During the Cold War, plenty of people were aware (I think?) that detonating enough nuclear bombs could lead to human extinction. Did any rabbis address whether the belief that Moshiach will come mean that a believing Jew is sure there will be no nuclear extinction (or something to that effect)?
(Rabbi J.D. Bleich in Tradition Fall 1984 says that because the Gemara says a king would not be punished for killing up to one sixth the world's population in war, that means a nuclear war killing more than that would be prohibited. But he's not addressing the question -- "does our faith claim there will not be nuclear extinction?")