The Doomsday Machine

Russia is apparently feeling nostalgic these days.

At one point, the camera zoomed in on something one of the military officers was reading: a binder opened to a page showing the weapon design.

“Maritime Multifunctional System Status-6,” a headline said, in block Cyrillic letters, above an illustration showing the submarine and a text in easily decipherable large letters explaining the weapon’s effects.

The submarine would “defeat important economic objects of an enemy in coastal zones, bringing guaranteed and unacceptable losses on the country’s territory by forming a wide area of radioactive contamination incompatible with conducting military, economic or any other activities there for a long period of time,” it said.

On Wednesday, Mr. Putin’s spokesman, Dmitri S. Peskov, told Russian news agencies that the cameras had accidentally filmed a secret document.

“Indeed, some secret data fell into the field of view of these cameras,” Mr. Peskov was quoted as saying by the news agency Interfax. Because the document was a genuine secret, he said, the video was subsequently removed from the channels’ websites. “We hope such a thing will never be repeated,” he said.