Are you under the impression the president can actually do it? It's not true, someone else at least needs to at least push another button. I'm 100% sure of what I said in regards to the USA, just not hidden nuke programs I wouldn't know about. No person in the USA can single handedly trigger a nuclear weapon launch.

Even the president needs someone else to push a button (and in those rooms there's also more than one person). There's literally no human that can do it alone without convincing at least 1 or 2 other people, depending on who it is.