Close Calls with Nuclear Weapons (2015)

Human and technical mistakes have nearly led to the accidental or mistaken launch of nuclear weapons.

On November 9, 1979, the unthinkable happened: computers at the North American Aerospace Defense (NORAD) headquarters indicated that a large-scale Soviet missile attack was underway.

Close calls have nearly led to the accidental launch of nuclear weapons.

A training tape showed an impending Soviet attack—and it was mistaken for reality. Photo: Robert Zimmerman

NORAD immediately relayed the information to high-level command posts and top leaders convened to assess the threat. Their response was swift: crews responsible for launching U.S. intercontinental ballistic missiles were put on the highest alert, nuclear bomber crews boarded their planes to prepare for takeoff, and the Airborne Command Post—the aircraft designed to allow the president to maintain control in the event of an attack—was put in the air, though without the president on board.

Six minutes later, when satellite data failed to confirm any incoming missiles, leaders decided against retaliation. It was later discovered that a technician had mistakenly inserted a tape containing a training exercise scenario into an operational NORAD computer, simulating a full-scale attack.

Following the incident, new processes ensured training tapes couldn't run on the main system—though Marshal Shulman, a senior State Department advisor, would later note that “false alerts of this kind are not a rare occurrence. There is a complacency about handling them that disturbs me.”

An equinox gone awry

Four years later, on September 26, 1983, a Soviet early-warning satellite indicated first one, then two, then eventually five U.S. nuclear missile launches. Tensions were high between the two countries—the Soviet Union had mistakenly downed a South Korean passenger plane just weeks before—and the officer on duty, Lieutenant Colonel Stanislav Petrov, had a matter of minutes to respond to the attack.

Stanislav Petrov's actions helped prevent a nuclear catastrophe. Photo: BT.com

With little additional information to go on, Petrov deemed the readings a false alarm, reasoning that “when people start a war, they don’t start it with only five missiles.”

Later investigations revealed that satellites mistook sunlight reflecting off the tops of clouds for missile launches. The orbit used by Soviet satellites was designed to minimize the chances of false alerts, but that night, shortly after the equinox, satellites, sun, and U.S. missile fields aligned in a way that maximized the sun’s reflection. 

Petrov’s actions earned him the nickname “the man who saved the world.” But if the satellite data had indicated the launch of a hundred missiles—or if a different officer had been on duty—this false alarm could have easily turned into catastrophe.

A surprising science experiment

A sounding rocket was mistaken as a precursor to nuclear war. Photo: Wikimedia

On January 25, 1995—fifteen years after the training tape close call—a Russian early warning radar detected an unexpected missile launch off the coast of Norway. The missile’s flight characteristics appeared similar to that of a U.S. submarine-launched ballistic missile, leading radar operators to believe that the missile might detonate a nuclear warhead high in the atmosphere, blinding Russian radars before a larger attack. Russian nuclear forces went on full alert, and President Boris Yeltsin activated his “football,” the device used to authorize nuclear launches.

Retaliation was avoided when Russian early warning satellites failed to find activity around U.S. missile siloes. The detected missile was actually the launch of a U.S.-Norwegian scientific rocket (the Black Brandt XII) on a mission to study the aurora borealis, or “northern lights.” Norway had notified Russia in advance of the launch, but the information didn’t reach the correct channels—and the innocuous science experiment escalated into a high-risk nuclear incident.

Close calls shouldn’t happen with nuclear weapons

Spanning multiple decades, these close calls and other safety incidents highlight the very real risks of keeping nuclear weapons on hair-trigger alert—risks that haven’t gone away.

Hair-trigger alert is the U.S. military policy that enables nuclear missiles to be rapidly launched. It needlessly truncates decision-making time, increasing the risk of a mistaken launch in response to false information. It also makes an accidental or unauthorized launch more likely. By removing missiles from hair-trigger alert—and preventing time-constrained decision-making about launching nuclear weapons—the United States would safeguard against future close calls, while encouraging reciprocity from Russia.

Download the full fact sheet, learn more about hair-trigger alert, or urge the president to act.

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