When you think about security passwords, your mind probably goes to lengthy, complex combinations; especially when we’re talking about something that can kill billions of people and start a worldwide nuclear holocaust. But things can sometimes be surprising.

For 15 years, from the Cuban Missile Crisis through much of the Cold War, the launch codes safeguarding some of America’s nuclear missiles were distressingly simple: eight zeroes. This astonishing fact remained a well-kept secret until Bruce Blair, a former Air Force launch officer and nuclear policy expert, disclosed it in the 2010s. The reality, as he and many others attested, exposes the uncomfortable truth about the fragility of nuclear safeguards prior to 1977.

The Code: 00000000

Minuteman intercontinental ballistic missiles (ICBMs) were designed to respond quickly to a nuclear threat, a cornerstone of the United States’ strategy of deterrence. During this era, missile launch crews operated from fortified underground launch control centers (LCCs), where a panel known as the Launch Enable Panel played a critical role. In order to “enable” the missile to receive a launch command, crew members had to dial in an eight-digit code.

Imagine setting up this passcode was up to you — what would it be? Probably something like “9C-fe-Z0–82” or something like that. But the US government chose 00,00,00,00,00,00 instead.

This wasn’t just a default setting—it was the operational code used for enabling launches. According to declassified documents and personal accounts, the standard procedure required crew members to verify that the code on the panel was indeed all zeroes before initiating the launch process.

In essence, anyone with access to the control panel and the authorization to launch would only need to turn a switch, confident that the code needed for enabling the missiles was already set to the simplest possible combination. There was no external code transmitted by higher authorities to validate the launch order.

Safeguards? Not So Much

At the time, the Strategic Air Command (SAC) insisted that the Minuteman system’s safeguards were foolproof. However, the reality told a different story. The “two-man rule” — requiring two qualified crew members to be present and in agreement during any step involving nuclear weapons — was frequently violated. Crew members often took naps or operated with reduced oversight, rendering this safeguard ineffective.

In his analysis, Bruce Blair noted that these procedures left the system vulnerable to unauthorized launches or potential accidents. The reliance on the eight-zero code, combined with lax enforcement of security protocols, represented a glaring weakness in the supposed fail-safe design of America’s nuclear deterrent.

The 1977 Reform: Introducing Real Codes

This precarious situation persisted until 1977, when the Strategic Air Command implemented a critical change known as Rivet Save. As part of this initiative, new Launch Enable Control Group panels were installed. These panels required the crew to input an unlock code received via an Emergency Action Message (EAM) from higher command authorities before enabling the missiles.

Instead of relying on the pre-set all-zero code, the new procedure introduced a dynamic code—typically a combination like P7P7P7P7P7P7—that was only transmitted during an authenticated launch order. Without this code, even a properly conducted key-turn sequence would fail to launch the missiles.

It’s not hard to see why the codes were changed, but the motivation behind this was actually twofold.

First, SAC sought to reduce the size of the launch crew force to cut costs, necessitating more frequent rotations for remaining personnel. To mitigate fatigue and the risk of human error, SAC allowed crew members to nap during shifts, requiring a technical solution to maintain security while a single crew member was awake. Second, the change addressed longstanding concerns about the vulnerability of the Minuteman system to unauthorized or accidental launches.

Important lessons

Despite this significant reform, the Air Force provided misleading information to Congress and the public for years. Official documents implied that the safeguard requiring a transmitted unlock code had always been in place. In reality, Blair insists the eight-zero code persisted until 1977, leaving the nuclear arsenal far less secure than officials claimed.

It took 15 years for a glaring vulnerability to be addressed—a delay that highlights that seems concerning today, and should have also seemed concerning at the time. Furthermore, the fact was obfuscated by some officials, which makes things even more concerning.

Bruce Blair’s revelations serve as a reminder that for much of the Cold War, the fate of global security hinged on very thin threads, like a code that was laughably easy to guess.

The launch code may no longer be all zeroes, but who knows how much of our global stability may still hinge on some very thin layers of security.