WASHINGTON - US officials believe Russia just tested a missile that, if perfected, could deliver nuclear warheads in a doomsday scenario.
Observers suspect an explosion that killed five scientists in a recent weapons test involved a nuclear-powered weapon, a missile capable of delivering warheads at long range and high speeds.
Russians call it the "Burevestnik." Defense experts see it as a wakeup call.
"The biggest nuclear threat remains Russia because they're the only other country with an arsenal that does pose an existential threat to the United States," Eric Edelman, former Under Secretary of Defense for Policy, tells CBN News.
Last year Russian President Vladimir Putin unveiled the development of Burevestnik, dubbed "Skyfall" by NATO.
"A vengeance weapon" is how Russia's government newspaper describes it - one designed to target remaining vital infrastructure after Russia's intercontinental ballistic missiles have already struck enemy territory.
Putin says "Skyfall's" nuclear propulsion would give it unlimited range and the ability to strike quickly. However, there's been a lot of trouble in its development.
The explosion on a testing platform in the Arctic was followed by a spike in radiation in a nearby city.
President Trump responded tweeting, "The United States is learning much from the failed missile explosion in Russia. We have similar, though more advanced, technology. The Russian "Skyfall" explosion has people worried about the air around the facility, and far beyond. Not good!"
Many experts are skeptical "Skyfall" will ever be perfected, but if the Russians can pull it off they agree it's impractical for anything short of all-out nuclear war.
"We've grown very complacent in all of this because since 1945 nobody has used nuclear weapons in anger and so I think there's a tendency to think no one will ever do this," Edelman says.
After years of alleged Russian violations, the US formally withdrew from the INF treaty which aimed to reduce the arsenal of nuclear weapons by both sides.
If the Russians do succeed in making "Skyfall" work they'll likely build hundreds of them which could launch a new Cold War-style arms race.