There was an idea that the key to the nuclear launch codes should be surgically implanted adjacent to the heart of the president’s assistant. If the president should desire to launch the nukes, they would have to personally cut down a man and pull the key from the man’s entrails.

It was essentially not done because it would be too effective.

I think there is a general distance to a lot of things in today's society. Very few of us have to farm or hunt for our own food, or clean an animal carcass. I don't have a strong view on the moral aspects of eating animals (I'm not a vegetarian or vegan), but I think it'll probably do some good if anyone that eats meat at some point slaughters, cleans and butchers one of the animals they eat.

It’s John von Neumann’s idea, at least from the biography I read. Before too much praise is heaped upon him, he also strongly argued for a nuclear first strike on Soviet Union before they got their own nuclear weapons because it was best strategy from game theory POV.