Next week marks 35 years since America and Russia narrowly avoided fighting a nuclear war—the kind that “cannot be won and must never be fought,” in the words of Ronald Reagan. It wasn’t the first time the two nations lived through such a close call, and stories like this can only remind us how much our continued existence may depend on individual humans’ handling of mistakes, accidents, misunderstandings and miscalculations—in other words, they remind us that a nuclear war is as likely to start through inadvertence as by design.
The “stand-off” in 1983 lasted minutes, not days like the Cuban Missile Crisis some 20 years earlier, but could have likewise led to full-blown nuclear war between the U.S. and USSR: Soviet early-warning systems detected a nuclear attack coming from the United States. The natural response would have been a counter-strike by Moscow. The result, as one Stanford professor wrote later, could have been “roughly a hundred million people blown apart, burned up and poisoned on the first day of the war.” (Within months, he estimated, the death toll could have reached a billion.)
The decision that prevented that from happening was made by a Soviet officer working the night shift at a secret military facility outside Moscow who determined, in the 10 minutes he had to make the call, that the alarm was false. His name was Stanislav Petrov.
According to several authoritative books by scholars of the Cold War, and one journalistic account, Petrov was a software engineer serving in the Soviet Space Defense Forces as a lieutenant colonel. As deputy head of the department of combat algorithms, Petrov spent most of his time fine-tuning the software of the Soviet Union’s early-warning system, Oko (an archaic—and Biblical—word for “eye”), which had been put into service in late 1982 even though it was not fully ready. He also regularly worked 12-hour shifts at Oko’s secret “nerve center” near Moscow to keep on top of the system.
Petrov was on such a shift on Sept. 26, 1983, when one of the nine Oko satellites watching U.S. intercontinental-ballistic-missile fields sent a signal that a missile had been launched from the Malmstrom Air Force base in Montana. The satellite then alerted Petrov’s center that four more Minuteman ICBMs had taken off and were headed toward the USSR. The alerts were automatically sent to the Soviet General Staff, but it was up to Petrov, as the commanding officer on duty at the center, to make the ultimate judgment on whether an American nuclear attack on Soviet Russia was really underway. The then 44-year-old officer had 10 minutes to decide.
Then, like now, tensions were running high between Moscow and Washington. Just a few weeks before, the Soviet Air Force had mistakenly shot down a South Korean passenger plane, prompting U.S. condemnation of a “massacre” by “Soviet aggressors.” About five weeks later, NATO would start Able Archer, a military exercise that involved raising the alert levels of U.S. nuclear forces in Europe to simulate preparations for an attack—war games that themselves would nearly prompt a nuclear conflagration.
Petrov himself recalled that his decision was based partly on an educated guess. He had been briefed many times that a U.S. nuclear attack would be massive, but the monitors showed only five missiles. Another factor, he said, was that Soviet ground-based radar installations, which search for missiles rising above the horizon, showed no evidence of an attack.
The false alarm was eventually traced to the Cosmos 1382 satellite, which picked up the sun's reflection off the tops of clouds and mistook it for missile launches. (As noted above, this was not the first such incident: In 1960, for instance, a comparable false alarm was triggered in the U.S. when one of its early-warning radars mistook the rising moon for a Soviet missile. Other stories abound, though exactly how close a “close call” each one was often remains a matter of debate.) After the 1983 scare, the glitchy computer program was rewritten to more effectively filter out such information.
The incident involving Petrov remained secret until the early 1990s when it was disclosed by Yuri Votinstev, who had been commander of the Soviet missile-defense forces at the time. Immediately after the incident, Petrov recalled, he had won praise from Votinstev. But then came an investigation, and Petrov’s questioners pressed him hard for failing to immediately write down the details of what had happened. Petrov was not surprised that he received no official recognition: If he had, he told an interviewer in 2004, “someone would have had to take the rap” for the glitch, most likely including some influential scholars who had designed the early-warning system.
Last year Petrov died, at the age of 77. When the news became widely known, some four months later, he was feted in headlines as “the man who saved the world”—the title of a 2014 documentary about his fateful choice. In his lifetime Petrov received awards in the U.S. and Germany, but he was famously humble about his accomplishment, saying he was just doing his job: “Foreigners tend to exaggerate my heroism,” he said in the 2004 interview. “I was in the right place at the right moment.”
Good thing he was. As Eric Schlosser reports in his acclaimed 2013 book “Command and Control,” Gen. George Butler, who took over the U.S. Strategic Air Command in 1991, once said, “[W]e escaped the Cold War without a nuclear holocaust by some combination of skill, luck and divine intervention, and I suspect the latter in greatest proportion.”
 Main source: David Hoffman, “The Dead Hand: the Untold Story of the Cold War Arms Race and Its Dangerous Legacy,” 2010. Additional sources: Gordon G. Chang, “Nuclear Showdown: North Korea Takes on the World,” 2006; Stephen J. Cimbala, “The Dead Volcano: The Background and Effects of Nuclear War Complacency,” 2002; and “On the Brink,” The Moscow News, May 29, 2004.
Photo by Oliver Killig. Stanislav Petrov receives the Dresden Prize, February 2013. (c) Alamy Stock Photo.