Drudge Report had a headline on 12-1-2013 that claimed that the PAL security protocol was illegally bypassed from 1962 through 1977 by setting the launch code to 00000000 on all Minuteman missiles.

To give you an idea of how secure the PAL system was at this time, bypassing one was once described as being “about as complex as performing a tonsillectomy while entering the patient from the wrong end.“ This system was supposed to be essentially hot-wire proof, making sure only people with the correct codes could activate the nuclear weapons and launch the missiles.

However, though the devices were supposed to be fitted on every nuclear missile after JFK issued his memorandum, the military continually dragged its heels on the matter. 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 weren’t 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, JFK’s Secretary of Defence. However, The Strategic Air Command greatly resented McNamara’s presence and almost as soon as he left, the code to launch the missile’s, all 50 of them, was set to 00000000.


So to recap, for around 20 years, the Strategic Air Command went out of their way to make launching a nuclear missile as easy, and quick, as possible. To be fair, they had their reasons, such as the fact that the soldiers in the silos in the case of a real nuclear war may have needed to be able to launch the missiles without being able to contact anyone on the outside. That said, their actions were in direct violation of the orders of the Commander-in-Chief, the President of the United States, during a time of extreme nuclear tension. Further, not activating this safeguard and lax security ensured that with very little planning, someone with three friends who had a mind to, could have started World War III.


Is there any evidence to support this claim? Was entering the 8 zeros all that was required to launch World War III (Or at least a missile)?

  • What would accept as evidence for or against? The article cites a first-person account from an expert but that could be considered anecdotal, I guess. – Oddthinking Dec 1 '13 at 9:54
  • Short of an "official" confirmation by the Pentagon or higher I don't think there's really anything that could confirm positively... – Shadur Dec 1 '13 at 12:25
  • To be fair, Richard Feynman was famous for showing how unsecured the nuke plans where in Los Alamos. Even an amateur picklocker like him could access all documents easily. He was in awe of a techinician that was said to be able to open all the safes too. Once he needed to open a safe to retrieve something and the general with the code was away, called the technician who proceeded to open the safe using the factory default code. Feynman had fantasized about the ability of this technician while he should have fantasized about the abysmally low security standards of the military. – Bakuriu Oct 27 at 20:05
  • (This also shows that stuff like "not changing default credentials", "reusing the code/password" etc is just as old as passwords/code themselves, well before anyone had need of tens of accounts online) – Bakuriu Oct 27 at 20:05

The source of the information is Bruce Blair. The New York Times has characterized him an "expert" during his time at the Brookings Institution.

He wrote in 2004,

The Strategic Air Command (SAC) in Omaha quietly decided to set the “locks” to all zeros in order to circumvent this safeguard. During the early to mid-1970s, during my stint as a Minuteman launch officer, they still had not been changed. Our launch checklist in fact instructed us, the firing crew, to double-check the locking panel in our underground launch bunker to ensure that no digits other than zero had been inadvertently dialed into the panel. SAC remained far less concerned about unauthorized launches than about the potential of these safeguards to interfere with the implementation of wartime launch orders. And so the “secret unlock code” during the height of the nuclear crises of the Cold War remained constant at 00000000.

(This is hearsay, but it's a more primary source than the source in the question. This answer can be improved by verifying Blair's testimony.)

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    note that this also isn't the launch code, it's the code that allows the warhead to be armed. Launching the weapon would rely on a coded order from the relevant command authority, decoded using a rapidly changing cypher which would give an authorisation sequence to verify that the order was authentic. – jwenting Dec 2 '13 at 7:14
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    @Jwenting - I think that if you can source that, it would be the right answer. The article above calls it the launch code, and infers that the missles could be launched by anyone simply by entering the 8 zeros – Chad Dec 2 '13 at 14:42
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    @Articuno there is no "launch code" per se. There's the PAL code required for arming the weapon, and a verification code to certify that the launch order is valid. After that, it's a matter of 2 crewmen turning their keys and maybe pressing a button (actual sequence depending on the specific weapon of course). – jwenting Dec 3 '13 at 9:32
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    I think the point of the article is that with the PAL code a crew could arm and launch a missle. There might be additional codes which were used to verify the correctness of an order, but if the crew decided that they were going to launch without orders, only the PAL code was going to be able to stop them. – DJClayworth Dec 3 '13 at 21:20
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    @DJClayworth yes, and such was of course a requirement for a retaliatory strike. Submarines for example had (unless several books I've read over the years on the topic, and NGC etc. documentaries about it were all wrong) a requirement to be able to launch on their own in case communications with central command authority were lost (and numerous retries to contact, etc. etc. of course). – jwenting Dec 5 '13 at 6:06

As mentioned in the other answer, this claim was made in 2004 by Bruce Blair, a former Minuteman launch officer. All sources for this story seem to trace back to Blair. He wrote:

Last month I asked Robert McNamara [...] what he believed back in the 1960s was the status of technical locks on the Minuteman intercontinental missiles. [...] McNamara replied [...] that he personally saw to it that these special locks (known to wonks as “Permissive Action Links”) were installed [...] and that he regarded them as essential to strict central control and preventing unauthorized launch.

[...] What I then told McNamara [...] elicited this response: “I am shocked, absolutely shocked and outraged. Who the hell authorized that?” What he had just learned from me was that the locks had been installed, but everyone knew the combination.

[...] During the early to mid-1970s, during my stint as a Minuteman launch officer, [...] [o]ur launch checklist in fact instructed us, the firing crew, to double-check the locking panel in our underground launch bunker to ensure that no digits other than zero had been inadvertently dialed into the panel. [...] And so the “secret unlock code” during the height of the nuclear crises of the Cold War remained constant at OOOOOOOO.

After leaving the Air Force in 1974, I pressed the service [...] to consider a range of terrorist scenarios in which these locks could serve as crucial barriers against the unauthorized seizure of launch control over Minuteman missiles. [...]

The locks were activated in 1977.

According to this January 2014 article at foreignpolicy.com,

A new wave of media coverage [of Blair's column] sparked by online media outlets last year prompted the House Armed Services Committee to ask about the issue, and the military responded by insisting "00000000" was never used.

The actual response from the Air Force is embedded in the article. Here are some excerpts (emphasis theirs):

The MM system has never used Permissive Action Links (PALs). PALs are strictly a nuclear aircraft crew device. Additionally, a code consisting of eight zeroes has never been used to enable or launch a MM ICBM, as claimed by Dr. Bruce Blair.

During the 1970s, 1980s and 1990s [the] second portion of the enable code was dialed into analog six digit thumbwheel switches located on the front of the Launch Enable Control Group (LECG) [...]

A daily check of the visible thumbwheel switches on the front of the LECG ensured that they were set to a standardized setting of “P7.” This provided a standardized “starting point” to help speed the process of flipping the switches in the event an enable code needed to be entered during time-critical missile launch procedures.

The document includes a photo of the LECG showing the six dials set to P7.

According to the article, Blair disputes the Air Force's claims. It's worth reading the whole article, but here are some excerpts:

[...] Blair [...] told Foreign Policy that [...] the new document [...] leaves out key basics from before 1977. That is when a program known as Rivet Save added in additional security precautions, including new launch codes [...]

"Before this real enable code system was adopted, there was no technical safeguard and both crewmembers were thus required to stay awake throughout the alert period in the underground capsule," Blair said. "Thus the document errs and misleads when it says that the 00000000 enable code system was never used."


Attempts to solicit comment from the Air Force were unsuccessful. However, Lance Lord, a retired four-star general and former nuclear launch officer, said he does not recall any codes including all zeroes ever being used. Like Blair, he recalled that both crew members in a launch control center were required to stay awake prior to Rivet Save being put in place in the late 1970s.

Below this point is only my own speculation. I'm inclined to disbelieve Blair for a few reasons:

  • I can't find evidence that any other former launch officers agree with him, and the article quotes one who disagrees.

  • The fact that the Minuteman system never used PALs makes me question his knowledge of the system. (I have no independent knowledge of this, but I'm assuming the Air Force wouldn't lie to Congress about something so easily checked.) The eight zeros versus six P7s discrepancy is also odd, but it could be related to the 1977 changes.

  • "The locks were activated in 1977" seems to refer to the deployment of a new security system, not enabling a neglected part of an old one.

  • Presuming Blair never had to enter a real enable code, it seems plausible that he might have misinterpreted the reason for setting the dials to a constant value, when it was actually just to make it easier to enter the real code, as the Air Force claimed.

  • McNamara may have reacted as described, but of course there's no guarantee that what Blair told him was true.

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