Russia's military and state-sponsored media have reacted to the news that the US will exit the Intermediate-Range Nuclear Forces Treaty with a fire and fury of their own, threatening to deploy a nuclear "doomsday device."

The US found Russia in violation of a key arms treaty, so the US scrapped the treaty and announced it would create its own formerly banned weapons.

Russia responded by saying it would build its own new nukes in retaliation, and its state-controlled media said nuclear war was now more likely.

Russian media also floated the possibility of launching an underwater nuclear doomsday device at the US's coast. Experts say this is perhaps the most dangerous weapon ever built.

Russia's military and state-sponsored media have reacted with a fire and fury of their own to the news that the US will exit the Intermediate-Range Nuclear Forces Treaty (INF Treaty), one of the last barriers preventing a full-on Cold War-like arms race in Europe — and there's already talk of a nuclear doomsday device visiting the US.

The INF Treaty banned land-based nuclear-capable missiles with a range between 300 and 3,200 miles in 1987 when Russia and the US had populated much of Europe with intermediate-range nuclear missiles. The ban eliminated this entire class of missiles and went down as one of the most successful acts of arms control ever.

The US and NATO concluded recently that Russia had spent years developing a banned nuclear-capable weapon, thereby making the treaty meaningless. The US responded by saying it would withdraw and design its own treaty-busting missiles. Russia said it would do the same, though many suspect they have already built the missiles.

Read more: France fires nuclear-capable missile in a rare show as Russia and US feud over arms treaty

But Russia's response to the US didn't stop there.

A BBC review of Russian newspapers, some state-owned and all adhering to state narratives or censored by the Kremlin, revealed some truly apocalyptic ideas.

"If the Americans deploy their new missiles near Russia's borders, and in response we deploy ours, then of course, the risk of [nuclear] conflict rises sharply," an arms-control expert told one paper.

"If US missiles are deployed in Poland or the Baltic states, they'll be able to reach Russia in minutes. In such an event, the way Russia currently conceives using nuclear weapons, as a retaliatory strike, becomes impossible, since there won't be time to work out which missiles have been launched against Russia, what their trajectory and their targets are," he continued. "This is why there is now a temptation for both us and for them to adopt the doctrine of a preemptive strike."

The expert said the INF Treaty's demise means both the US and Russia now have to consider nuking the other at the first sign of conflict because missile attacks won't be as predictable as longer-range salvos from the continental US and Russia's mainland.

But the expert neglects to mention that US and Russian nuclear submarines can already fire from almost anywhere at sea, already confusing targets and trajectories and taking minutes to reach Russian forces.

Read more: In a fiery warning to rivals, Putin says any country that nukes Russia will 'drop dead'

Finally, Russian media turned to what's quickly becoming a propaganda crutch in communicating Moscow's might: the doomsday device.

Russia recently said it built one of the most devastating nuclear weapons of all time in the form of an undersea torpedo with a 100-megaton nuclear warhead that's designed to be unstoppable against all missile defenses and create tsunami-size waves, and a radioactive hellstorm that stomps out life on earth for thousands of square miles for decades.

Read more: Russia just showed off a potentially world-ending nuclear 'doomsday' torpedo that the US can't stop

Since they announced the weapon, they've already used it to threaten Europe. But now with the INF Treaty in tatters, a military expert told a Russian paper that the doomsday device could see use.

"It cannot be excluded that one of the Poseidon with a 100 megaton nuclear warhead will lay low off the US coast, becoming 'the doomsday weapon.' Thus an attack on Russia, will become a suicidal misadventure," the paper said.

The paper also declined to mention that the US and Russia's nuclear posture already guarantees any mutual nuclear exchanges would lead to the total destruction of both countries.

Read more: A new Russian video may show a 'doomsday machine' able to trigger 300-foot tsunamis — but nuclear weapons experts question why you'd ever build one

Russia's Poseidon doomsday device doesn't change the mutually assured destruction dynamic between Washington and Moscow. It provides only a way to destroy more natural life in the process.

Russia's media may swerve into bombast, but Russia's actual military has already announced plans to build more weapons and extend the range of weapons to counter the US in what experts peg as the next great nuclear standoff.