There was someone who worked in Washington who made a proposal that the nuclear launch codes should be printed on a little capsule that was surgically implanted inside a man who would travel around with the president, in kind of the same way that the briefcase or whatever-it-is travels around with him under the current system.
The deal was, if the president wanted to launch a nuclear strike, he had to take a big knife and kill the man to cut him open to get to the capsule. Kind of come to grips on an individual level with what he was dealing with, and what it meant on at least some level, instead of just pushing some buttons in an air conditioned office.
I don't think this was ever meant as a serious proposal. The person who invented it was just trying to make a point. But it did get relayed to at least one person who worked in the Pentagon who got very upset at the idea and started arguing against it. What if, he said, the president looks at what's in front of him and can't do it. That would be terrible.