On Friday, as Russian Federation tanks and troops poured across the border into eastern Ukraine, Vladimir Putin talked about his country’s most destructive weaponry. “I want to remind you that Russia is one of the most powerful nuclear nations,” he said. “This is a reality, not just words.” Russia, he told listeners, is “strengthening our nuclear deterrence forces.”

That same day, Putin used a term for eastern Ukraine meaning “New Russia.” So when he refers to repelling “any aggression against Russia” and speaks of “nuclear deterrence,” as he did on Friday, the Russian president is really warning us he will use nukes to protect his grab of Ukrainian territory.

For more than a generation, nuclear weapons were considered defensive only. In a few short sentences on Friday, however, Putin made these devices offensive in nature, just another tool to be employed by an aggressor. And to highlight his threat, on Aug. 14 at Yalta, the Crimean city he had seized this year, Putin mentioned “surprising the West with our new developments in offensive nuclear weapons about which we do not talk yet.”

Also in Yalta, where the Duma was meeting, the Russian leader spoke about renouncing the 1987 Intermediate-Range Nuclear Forces Treaty between the U.S. and Russia. The treaty outlaws ground-launched ballistic and cruise missiles with ranges between 300 and 3,400 miles and is a foundation of the post-Cold War peace.

It is one thing to talk about withdrawing from the pact—Putin has been doing that since 2007—it is another to violate it, which Putin has apparently been doing since 2008, when Russia began testing cruise missiles again. And when the State Department’s Rose Gottemoeller raised the concern in May of last year, Russian officials tried to shut down the dialogue. According to The New York Times, they “said that they had looked into the matter and consider the issue to be closed.”

“Administration officials said the upheaval in Ukraine pushed the issue to the back burner,” the paper reported of the INF violation. Putin, with his comments Friday, just moved it to the front of the stove.

And not just in the European kitchen. If Putin manages to intimidate the West with his not-so-veiled promises to incinerate Ukraine’s defenders, other aggressors may think they too can employ his threatening tactics. For instance, both North Korea and China have recently talked about unleashing Armageddon.

Perhaps we can ignore the ranting of the Kim regime, but Chinese nuclear threats are particularly worrisome. China’s flag officers have, for two decades, been issuing belligerent warnings about Beijing’s willingness to use nukes to seize Japan’s outlying islands or Taiwan, but the threats took on an especially belligerent tone last October.

With no apparent provocation, the main outlets of Chinese state media—People’s Daily, China Central Television, and PLA Daily, among others—ran identical articles that month about how Chinese submarines launching ballistic missiles tipped with nuclear warheads could kill tens of millions of Americans in Seattle, San Francisco, Los Angeles, San Diego, Boston, New York, Philadelphia, Baltimore, Portland in Maine, and the Navy towns of Annapolis and Norfolk. Those Chinese reports also talked about radiation deaths in Chicago.

On Thursday, a nuclear exchange was, at least for most people, inconceivable. Yet now that a reckless Putin has raised the stakes on Friday by making nukes just another appliance of aggression, an incident of mass slaughter looks dangerously real and perilously close.