Don't just take my word for it.
Mind blowing.
Holiest of holy shit.
Mind blowing.
In fact, it was noted that a full 20 years after JFK had order PALs be fitted to every nuclear device, half of the missiles in Europe were still protected by simple mechanical locks. Most that did have the new system in place werent even activated until 1977.
Those in the U.S. that had been fitted with the devices, such as ones in the Minuteman Silos, were installed under the close scrutiny of Robert McNamara, JFKs Secretary of Defence. However, The Strategic Air Command greatly resented McNamaras presence and almost as soon as he left, the code to launch the missiles, all 50 of them, was set to 00000000.
Holiest of holy shit.