It is the scale of things, being embarrassed by the people you are invading next door doesn’t lead to being so annoyed Putin ends his and Russia’s existence, in nuclear fire.
A phone call from Putin would not lead the military to launch a nuclear war when they know Russia is not being attacked by anyone or even being threatened by anyone.
It would basically be launching nuclear war while at peace.
Due to the immediate possible threat of nuclear war, no one is allowed to second guess any order to launch. There is not enough time to allow that second guess. That is why the President is the most powerful individual on the planet, and the same goes for Putin and Xi.