How I think nuclear war would start

This is just my assumption but I think the long waited Nuclear War would start when USA or Russia would start pushing it’s opponent so much while believing the opponent won’t go down to using Nukes.

Nuclear war need that sort of carelessness and negligence from one or either side. Currently we are seeing USA is pushing Russia while saying Nuclear attack would be irresponsible, it would be unbelievable. Basically what they are saying is, it won’t happen. But what I believe will happen is, Russia will keep warning USA, and USA will keep pushing Russia believing these warning are just warnings until one day it finally happens