I think that since both sides know that playing with fire could lead to the total destruction of humanity, it is unlikely that they will start playing with atomic bombs. But in wars you never know. When the conflict starts to escalate sometimes things get out of hand.
I think we should take into account that those who have the power to use nuclear weapons know very well that they will preserve their lives in their underground shelters, along with all those who are important to them. What is important to them is to save enough people to be able to start anew when the nuclear winter is over. When we take all this into account, along with the fact that some of the famous people of the world are advocating the depopulation of the world, then we cannot feel too calm, although we should always count on that spark of human reason and humanity.