MOSCOW— If this isn’t the scariest interactive exhibit in the world, it’s way up on the list.
Deep beneath the Russian capital, the musty, cavernous control room of the secret bunker goes dark. A green map of the Northern Hemisphere lights up a large screen. Smaller lights glow and blip on a hulking console.
A man’s emotionless voice counts out a numeric code. Another man turns a key that arms the intercontinental ballistic missiles. Then he turns a second key to launch them. The screen shows the projectiles rising from their silos like giant metal cobras, blasting off to obliterate their targets half a world away. Or so it appears.
“It was a great feeling to destroy America,” says the key man, a Swiss visitor chosen to take part in the display. His laugh seems misplaced, and a bit unsettling, given the new and rising tensions between Russia and the West.
This nuclear strike is, of course, a simulated one — not the start of World War III — and it takes place in a Cold War relic: an underground former top-secret Soviet military complex designed to survive a nuclear attack and launch a counterstrike. Visitors get hands-on lessons on the dangers of the US-Soviet arms race, which for four decades threatened to turn the Cold War into a thermonuclear one.
This the Cold War museum at Bunker-42 on Taganka,, and it has been letting its visitors touch off nuclear warfare for years, a show that seemed — until recently — a script from another time. But in the wake of recent events in Russia and Ukraine, it is a reminder of the worst that could happen when tensions boil over.
The US government this week accused the Kremlin of violating a landmark 1987 nuclear weapons treaty. This further strained a relationship that has been deteriorating rapidly over US sanctions leveled to punish Russia for its support of Ukrainian separatists. US leaders say the rebels used a missile supplied by Moscow to shoot down Malaysian Airlines Flight 17, killing 298 people.
Neither country’s leaders have suggested that the confrontation over Ukraine will lead to a nuclear conflict, but one of Russia’s most influential voices recently threatened one.
In March, Dmitry Kiselyov, the host of a popular news program on Russia’s main state-owned channel, and the voice of the Kremlin’s anti-Western propaganda campaign, reminded viewers that Russia is capable of turning the United States into “radioactive dust.” Both countries still have thousands, and deploy hundreds, of nuclear warheads.
The guides at Bunker-42 stay out of politics and emphasize that the museum is entirely educational.
“By its very existence it will long remind the future generations about the period of the Cold War, when humanity was perched on the edge of its own self-destruction,” said Fyodor Belousov, the guide on a recent tour.
In keeping with this mission, he avoided clarifying which country launched first in the simulated strike, although the visitor who turned the key, Reto Wachter of Switzerland, said he believed he was launching a Soviet missile attack against the United States.
Commissioned in the early 1950s, when nuclear conflict seemed a constant threat, the facility was designed for 600 personnel, who operated more than 200 feet below the surface in a 75,000-square-foot network of claustrophobic, dimly lit tunnels and blocs under the Taganka neighborhood of central Moscow.
Beneath a nondescript building erected to conceal the entrance, the facility — protected by hermetic two-ton doors, 20-foot-thick reinforced concrete walls, and its depth — could withstand the explosive force and radiation of a 10-megaton nuclear detonation in Moscow, Belousov said.
It could also survive a direct hit by a 40-kiloton warhead, he said. Good thing: Forty kilotons was within the range of yields of the warheads carried by the US Pershing II missile, which was intended to attack just such hardened, buried military sites, said Matthew Bunn, professor of practice at the John F. Kennedy School of Government at Harvard University.
“The odds that we knew about it are very high,” Bunn said. (The Soviets probably knew about our secret bunkers, too, he said.)
The museum is 18 floors down a narrow staircase, and visitors utter oohs and ahhs when they see just how far the first tunnel stretches into subterranean nothingness. (Those turn to ughs at the end of the tour, when visitors learn they have to climb back up on foot.)
The simulated launch is played out in the control room, where a security guard warns visitors to not to take pictures: Though decommissioned well before the museum opened in 2006, Bunker-42 still contains authentic equipment that museum operators say is still classified.
The complex had enough food, water, and power for its occupants to survive 30 days in underground isolation. That was tested once, during the Cuban Missile Crisis in October 1962, when 2,500 people hunkered down in the bunker for 10 days.
“You can imagine how hard it was to be here when the world was on the brink and any second nuclear war could break out,” Belousov said.
For a sense of how that might have felt, visitors are herded into a tunnel that suddenly goes dark. A siren blares, red lights flash, and an extremely loud, sustained explosion erupts overhead.
“The territory of our country has been hit with a 10-megaton warhead,” a voice intones. “The supreme commander of the USSR has decided to launch a retaliatory strike.”
The voice doesn’t name the adversary, but Belousov said that a counterstrike would have reached US territory in 28 minutes.
Bunn said that Moscow was targeted by as many as 80 US nuclear weapons. It’s hard to say how the site would have come through that onslaught. But that’s not really the point.
“I think it’s worth reminding people that there are still thousands of nuclear weapons in the world,” Bunn said.David Filipov can be reached at David.Filipov@globe.com. Follow him on Twitter @davidfilipov.