In 2015, Russia television "accidentally" showed a glimpse of plans for a proposed new 100-megaton autonomous torpedo designed to destroy American ports and poison the coastline of any adversary it targets. Analysts were left wondering whether the blueprints were a sign that Moscow was returning to the good old days of bizarre Cold War weapons development—or just bluffing to keep the Yankees off balance.

The U.S. government still appears to believe that the weapon is a real Russian program, according to a leaked draft of the Trump administration's forthcoming Nuclear Posture Review obtained by the Huffington Post.

Jeffrey Lewis, a scholar at the Middlebury Institute of International Studies, first noticed a brief reference to the weapon in a section of the report listing "New Nuclear Delivery Vehicles Over the Past Decade." The grainy, photocopied graphic shows the outline of "Status 6," an abbreviation of Russia's designation for the weapon, alongside the acronym "AUV"—short for autonomous underwater vehicle—in a column detailing sea-based nuclear modernization efforts of Russia and other countries over the past seven years. The review also references Russia's development of a "nuclear-armed, undersea autonomous torpedo" that matches the description of the weapon originally shown on Russian TV.

Little is known about the oceanic dirty bomb outside of its brief debut in Russian media. A November 2015 Channel One broadcast covering a meeting between Russian President Vladimir Putin and senior military officials briefly showed a slide with an artist's rendering of the weapon—a glimpse described as an accidental leak of classified information by the Kremlin and assessed by some Russia watchers as an entirely intentional threat from Moscow.

The slide asserts that the drone can travel at a speed of more than 100 knots for as far as 10,000 kilometers, while sporting a 100-megaton nuclear warhead. Noting that “an important object of war is against the economy in coastal regions," it claims the "Status-6 Oceanic Multipurpose System" is capable of "guaranteeing mortal damage to the territory of countries, creation of zones of radioactive pollution unfit for carrying out military, economic and other activities."

A year later, the Washington Free Beacon carried a report claiming that the Pentagon had detected a Russian Sarov-class submarine carried out a test of the Status-6 weapon in November 2016. An intelligence assessment leaked to the outlet affirmed that the weapon, known to the Defense Department as "Kanyon," would carry megaton-class nuclear warheads.

The prospect of a new quiet, long-range drone that can swim up to the U.S. coast and obliterate a port along with the environmental viability of the surrounding areas was unnerving enough. That it came amidst Russia's newfound assertiveness to challenge the West only added to the concern among American policymakers.

As East-West relations have soured following Russia's invasion of Ukraine and annexation of Crimea, Moscow has engaged in a series of nuclear saber-rattling gestures. The Trump administration cited Russia for what they say is a violation of the 1987 Intermediate-Range Nuclear Forces Treaty, designed to eliminate missiles with ranges between 500 and 5,500 kilometers, sanctioning Russia for deploying a new kind of ground-launched cruise missile with a range it says is prohibited by the agreement.

Russia's military has also embarked on a less-than-subtle campaign to remind the West of its willingness and ability to use its nuclear arsenal weapons, resuming long range nuclear bomber and submarine patrols, even going so far as to carry out a mock nuclear strike exercise against Sweden.

As sci-fi as the Status-6 sounds, its conceptual origins are decidedly Cold War retro. Starting in the 1940s, the golden era of nuclear weapons design, both the U.S. and Soviet Union developed and deployed their own varieties of a nuclear torpedo with relatively low yields aimed at taking out enemy ships and submarines.

The Soviets, however, came closest to building a weapon like the Status-6 as far back as 1949. "The T-15 nuclear torpedo program started in 1949 and was intended to be the first nuclear weapon employed by the Soviet Navy," said H.I. Sutton, an author and defense analyst specializing in submarine warfare. Like the Status-6, the torpedo would've used a nuclear warhead with megatons of explosive power to take out ports like Pearl Harbor and Gibraltar rather than enemy naval vessels.

"The project was so important that Russia’s first nuclear powered submarine, the November Class, was designed around a single torpedo tube for a T-15," according to Hutton, but the program ended shortly after Soviet designers realized it would be easier to accomplish the task with ballistic missiles instead of torpedoes.

But the Status-6, with a longer range, smarter software, represents an altogether more advanced weapon than its Cold War predecessor, and one which not just the Trump administration appears to be taking seriously. "Russia commissioned a special submarine called Sarov which can only be explained as a test platform for a massively oversized torpedo," said Sutton. Submarines aren't cheap, and Russia, strapped for defense rubles in the face of Western sanctions and declining energy prices, doesn't exactly have the cash to flop down on a bluff.