During the Cold War, the code meant to prevent unauthorized launching of the United States’ arsenal of Minuteman nuclear missiles was apparently “00000000.”
At the ’60s, a Permissive Action Link (PAL) system was put in place to ensure that nuclear missiles couldn’t be launched without the right code.
However, the Strategic Air Command (SAC) thought that this was an additional obstacle and could prove costly during the event of an actual war by wasting precious minutes to launch a counter attack.
So, they changed the codes to 00000000 for all 50 of the missile silos.
Millions of lives were protected by a simple code of eight zeroes for nearly fifteen years.
However, amid the renewed hype over the easily cracked code, a crucial element has been largely overlooked: Though the physical code preventing an unauthorized missile launch may have been all zeroes, the process of arming the actual nuclear warhead was much more involved, according to the National Museum of the U.S. Air Force. This is the seemingly made-for-Hollywood process involving the simultaneous turning of keys, “Emergency War Order” safes and verified launch codes, which presumably were not all zeros.
So while rogue officers or Soviet spies could have gained access to a missile by dialing “00000000” — which certainly may have led to disastrous consequences on its own — actually launching a nuclear weapon would have required significantly more work.