Code was just a general statement. No matter which country, this thing would not be placed in one's hand. Normally, they would be split into three parts—the highest leader, the prime minister, and the controller of the nuclear missile like the highest commander. When the three codes were found, they needed to be joined before they could be inputted into the system. Then one had to possess two or more keys to unlock the lock at the same time to fire the missile, and the target could not be changed—the target for each missile had been set beforehand.
Happy Valentine's Day