Well there was this one Russian guy who prevented a nuclear exchange between Russia and the US. It was a spurious ding on his radar that said we launched and he was being yelled at to retaliate but he didn’t. http://gimundo.com/news/article/the-man-who-saved-the-world-by-doing-nothing/
Russia now has a doomsday device set up to autolaunch missiles since humans may refuse the order. WIRED wrote about it.