Asked to comment the following day, Putin’s spokesman claimed the image had appeared in the nightly news by mistake. But the Kremlin’s mouthpiece newspaper then followed up with details. The warhead inside Status-6, it said, would likely be covered in cobalt, an element which would “guarantee the destruction of all living things” once it was irradiated and scattered by a nuclear explosion.

Vladimir Dvorkin, a retired major general of the Russian strategic rocket forces, remembers such designs from his days developing nuclear submarines for the former Soviet Union. “It’s an old Soviet brainchild,” he told me by phone from Moscow. But he never expected to see it revived. In the 1990s and during first two years of Putin’s presidency, Dvorkin headed the main nuclear research directorate of the Russian Ministry of Defense. The emphasis throughout those years was on cooperating with the U.S. to secure nuclear stockpiles and keep them out of the hands of terrorists.

The reemergence of Status-6—even if more as a propaganda ploy than as an actual weapon—shows just how far relations have fallen since then. “The idea is to creep up on the seaboard of the United States and set off a massive nuclear explosion,” says Dvorkin. “It’s being revived in order to spook the West.”