The premise I heard and I agree with is that there is no such thing as a limited nuclear war. Brinkmanship no longer exists, when so many fools believe that you can have a Tactical Nuclear exchange without escalating to Global Thermonuclear War.
Wake up everybody! If a nuclear weapon by either side is used, after the first exchange, the side that believes it is about to lose will go all in with Strategic Nuclear Weapons. When that happens, the other side, within minutes, will launch its Strategic Nuclear Weapons with warheads of each one passing each other on the way to mutual destruction.
Ukraine doesn’t have nukes.