https://redlib.catsarch.com/r/stupidpol/comments/1rioop0/familiarize_yourself_with_the_samson_option/
I'm a little reluctant to link to Wiki but at the moment it covers the basics pretty well, better than any of the essays I see online that Google is willing to hand me. Anyway, the gist is this, if Israel looks like it's going to lose badly to the point where the survival of Israel looks doomed, it has a plan to use nuclear bombs on its enemies and drag them all down with it. It's a unique policy, not really Mutually Assured Destruction so much as One Last Radioactive Hissy Fit.
You should never ever underestimate the importance of nuclear weapons when gauging the behavior of countries and their motivations. It is the primary source of power and leverage that forces the international community to take a country seriously militarily. Allowing Israel to acquire nukes is arguably the biggest international blunder of the post-WWII era, because it forces the world to tip-toe around a tiny paranoid maniac-tier ethnonationalist land-hungry country that periodically invades its neighbors.
Sy Hersh has a book about it, too.
