It's supposed to be the stuff of science fiction: A device that triggers a nuclear holocaust in the event of a U.S. strike against Russia.
But the "Dr. Strangelove"-esque technology isn't just fantasy. The Cold War-era Soviet "doomsday machine" was -- and might still be -- very much a reality.
From interviews with former Soviet arms officials and Defense Department documents, Nicholas Thompson, a senior editor for Wired magazine and author of "The Hawk and The Dove: Paul Nitze, George Kennan, and the History of the Cold War," learned that the system was built 25 years ago to ensure a nuclear retaliation if Russia were attacked by the U.S.
When triggered by an elaborate system of sensors placed around Russia, the program was designed to launch a fleet of missiles at major targets across the U.S. Some experts estimate that a Russian counter-strike could have killed more than one hundred million Americans.
And though the Iron Curtain was lifted more than a decade ago, it's believed that the "doomsday" system was never retired, according to Thompson.
"The Soviets really did fear that the U.S. was going to launch a nuclear strike," he said. "It's still in place, but it's not as though they're sitting around waiting for America to strike. It's on lower alert."
The top-secret Russian program, he continued, virtually guaranteed the ability to strike back, even if the entire chain of command had been wiped out.
Now that the Cold War is over, the closely-guarded system, code-named Perimeter, is no longer a secret. Experts on the Russian military have published articles about it since the early 1990s.
But top American and Russian officials are still reluctant to discuss it, Thompson said.
In a piece written last month for Wired, Thompson said that when he told former CIA director James Woolsey about the USSR's doomsday device, he responded, "I hope to God the Soviets were more sensible than that."
For his article and book, Thompson spoke at length with Valery Yarynich, a former colonel with the Soviet Strategic Rocket Forces and Soviet General Staff, who helped build the Perimeter system.
But Thompson said that the program is still so under wraps that Yarynich is concerned that his transparency puts him at risk. Apparently, Thompson wrote, a Russian official who spoke with Americans about the program died after a mysterious fall down a flight of stairs -- an ominous sign for others considering speaking.
The Perimeter system Yarynich helped build involved four steps. Designed for crisis situations, officials first had to turn the program on. Once activated, it would continuously scan for signs of a nuclear explosion with seismic, radiation and air pressure sensors.
If the sensors detected a nuclear attack, the program would attempt to contact political and military leaders. If the system could not communicate with the leaders, then it would determine that it was time for retaliation.
But the "doomsday machine" wasn't totally automatic and computerized.
Once the first three conditions were met, authority to launch the counter-attack returned to humans -- officers stationed beneath the surface of the Earth in a concrete bunker, presumably protected from any nuclear blast.