The scary part of nuclear deterrence is indeed whether it is able to continue to prevent nuclear warfare. As you imply, technical innovations can change the pic

The scary part of nuclear deterrence is indeed whether it is able to continue to prevent nuclear warfare. As you imply, technical innovations can change the picture. And nuclear warfare with limited escalation remains a scary possibility. Especially between countries that don't have MAD capability. Let's be glad that so far cool heads prevailed.