There's a big difference between the 1940s and today... and that difference is nowadays we have a certain group of "people" who hate the World, don't have any children or grandchildren and don't care about the future. In their mind we are overpopulated and wouldn't mind if a few billion of us would be gone (Kind of like that Thanos character from the Marvel movies). They are extinctionist, there's a few in this very forum... and of course spread through many countries... and the scary part is many a billionaires or CEO of a huge tech company. Now imagine people like that in charge of nuclear weapons. They don't care about the future... they would push AI without regulation, or put more chemicals in our food... and if given the chance consider nuclear weapons as an option.