Agreed. It starts with making provocative statements about nuclear weapons. People that think "that just can't happen" should consider possible pressure points that could change that certainty.
One possible scenario is that US (not really)/European leadership does not offer an "off-ramp" to Putin to deescalate. Some people see that as a sign of weakness. That's a fair point.
But if so, US/European leadership is going to have to decide on how far they will go to sanction Russia. Russia is not North Korea - they will not behave as a country in the same manner. What's next - blockade of humanitarian aide to all non-Russian held areas of the Ukraine? To Russia? Expel Russian nationals from Europe and the US? Nationalize Russian businesses operating in the US and Europe?
The rhetoric needs to cool—and cool quickly.
The flaw in command in control can happen when communications is broken—for any reason.
Listen to the doubletalk and vague assurances on this relatively recent close call: