There have been many 'close calls' in regards to launch of nuclear weapons (
Wiki link) but the closest was on October 27 1962. Disaster was averted, the bottom line is that world leaders are usually the type to bluster and show off regarding their nuclear arsenal but none of them have the balls to go down in history as the guy that ended human civilisation.
No, the thing that will end us is climate change caused by human greed and capitalism. Humans may live to see the 22nd century, we will not see the 23rd. Life on this planet will continue just fine but the human species will come to an end in the 6th mass extinction event that is already well underway (
Wiki link) and by now we're too far in to stop it (I estimate we passed the point of no return in the late 60s or early 70s). That's fine though, mass extinctions are a vital part of evolution on this planet. Our only hope as humans is to seed human colonies on other planets/solar systems before that happens.
But I have no children, I'll be long dead by then, so I don't care. Yes I'm aware that this is
exactly the attitude that got us in this mess in the first place, but c'est la vie, maybe that's why humans don't deserve to be the dominant species on this planet anymore.