There have been hundreds of accidents involving nuclear weapons since 1945. Illustration by Shout

On January 25, 1995, at 9:28 A.M. Moscow time, an aide handed a briefcase to Boris Yeltsin, the President of Russia. A small light near the handle was on, and inside was a screen displaying information indicating that a missile had been launched four minutes earlier from somewhere in the vicinity of the Norwegian Sea, and that it appeared to be headed toward Moscow. Below the screen was a row of buttons. This was the Russian “nuclear football.” By pressing the buttons, Yeltsin could launch an immediate nuclear strike against targets around the world. Russian nuclear missiles, submarines, and bombers were on full alert. Yeltsin had forty-seven hundred nuclear warheads ready to go.

The Chief of the General Staff, General Mikhail Kolesnikov, had a football, too, and he was monitoring the flight of the missile. Radar showed that stages of the rocket were falling away as it ascended, which suggested that it was an intermediate-range missile similar to the Pershing II, the missile deployed by NATO across Western Europe. The launch site was also in the most likely corridor for an attack on Moscow by American submarines. Kolesnikov was put on a hot line with Yeltsin, whose prerogative it was to launch a nuclear response. Yeltsin had less than six minutes to make a decision.

The Cold War had been over for four years. Mikhail Gorbachev had resigned on December 25, 1991, and had handed over the football and the launch codes to Yeltsin. The next day, the Soviet Union voted itself out of existence. By 1995, though, Yeltsin’s popularity in the West was in decline; there was tension over plans to expand NATO; and Russia was bogged down in a war in Chechnya. In the context of nuclear war, these were minor troubles, but there was also the fact, very much alive in Russian memory, that seven and a half years earlier, in May, 1987, a slightly kooky eighteen-year-old German named Mathias Rust had flown a rented Cessna, an airplane about the size of a Piper Cub, from Helsinki to Moscow and landed it a hundred yards from Red Square. The humiliation had led to a mini-purge of the air-defense leadership. Those people did not want to get burned twice.

After tracking the flight for several minutes, the Russians concluded that its trajectory would not take the missile into Russian territory. The briefcases were closed. It turned out that Yeltsin and his generals had been watching a weather rocket launched from Norway to study the aurora borealis. Peter Pry, who reported the story in his book “War Scare” (1999), called it “the single most dangerous moment of the nuclear missile age.” Whether it was the most dangerous moment or not, the weather-rocket scare was one of hundreds of incidents after 1945 when accident, miscommunication, human error, mechanical malfunction, or some combination of glitches nearly resulted in the detonation of nuclear weapons.

During the Cold War, there were a few occasions, such as the Cuban missile crisis, in 1962, when one side or the other was close to a decision that was likely to start a nuclear war. There were also some threats to go nuclear, though they were rarely taken completely seriously. In 1948, during a dispute with the Soviets over control of Berlin, Harry Truman sent B-29s to England, where they would be in range of Moscow. They were not armed with atomic bombs, but they were intended as a signal that the United States would use atomic weapons to defend Western Europe.

In 1956, during the Suez crisis, Nikita Khrushchev threatened to attack London and Paris with missiles if Britain and France did not withdraw their forces from Egypt. And, in 1969, Richard Nixon ordered B-52s armed with hydrogen bombs to fly routes up and down the coast of the Soviet Union—part of his “madman theory,” a strategy intended to get the North Vietnamese to believe that he was capable of anything, and to negotiate for peace. (The madman strategy was no more effective than anything else the United States tried, short of withdrawal, in the hope of bringing an end to the Vietnam War.)

But most of the danger that human beings faced from nuclear weapons after the destruction of Hiroshima and Nagasaki had to do with inadvertence—with bombs dropped by mistake, bombers catching on fire or crashing, missiles exploding, and computers miscalculating and people jumping to the wrong conclusion. On most days, the probability of a nuclear explosion happening by accident was far greater than the probability that someone would deliberately start a war.

In the early years of the Cold War, many of these accidents involved airplanes. In 1958, for example, a B-47 bomber carrying a Mark 36 hydrogen bomb, one of the most powerful weapons in the American arsenal, caught fire while taxiing on a runway at an airbase in Morocco. The plane split in two, the base was evacuated, and the fire burned for two and a half hours. But the explosives in the warhead didn’t detonate; that would have set off a chain reaction. Although the King of Morocco was informed, the accident was otherwise kept a secret.

Six weeks later, a Mark 6 landed in the back yard of a house in Mars Bluff, South Carolina. It had fallen when a crewman mistakenly grabbed the manual bomb-release lever. The nuclear core had not been inserted, but the explosives detonated, killing a lot of chickens, sending members of the family to the hospital, and leaving a thirty-five-foot crater. Although it was impossible to keep that event a secret, the Strategic Air Command (SAC), which controlled the airborne nuclear arsenal, informed the public that the incident was the first of its kind. In fact, the previous year, a hydrogen bomb, also without a core, had been accidentally released near Albuquerque and exploded on impact.

Soon after the successful Soviet launch of Sputnik, in 1957, missiles became the preferred delivery vehicle for nuclear warheads, but scary things kept happening. In 1960, the computer at the North American Air Defense Command (NORAD) in Colorado Springs warned, with 99.9-per-cent certainty, that the Soviets had just launched a full-scale missile attack against North America. The warheads would land within minutes. When it was learned that Khrushchev was in New York City, at the United Nations, and when no missiles landed, officials concluded that the warning was a false alarm. They later discovered that the Ballistic Missile Early Warning System at Thule Airbase, in Greenland, had interpreted the moon rising over Norway as a missile attack from Siberia.

In 1979, NORAD’s computer again warned of an all-out Soviet attack. Bombers were manned, missiles were placed on alert, and air-traffic controllers notified commercial aircraft that they might soon be ordered to land. An investigation revealed that a technician had mistakenly put a war-games tape, intended as part of a training exercise, into the computer. A year later, it happened a third time: Zbigniew Brzezinski, the national-security adviser, was called at home at two-thirty in the morning and informed that two hundred and twenty missiles were on their way toward the United States. That false alarm was the fault of a defective computer chip that cost forty-six cents.