Russian state TV host Dmitry Kiselyov has a reputation for attacking the West.
Critics call him the "Kremlin's chief propagandist". And like many other top Russian officials, he is on the Western sanctions blacklist.
But the warning he delivered to Washington in last night's edition of his show News of the Week was, even for him, particularly dramatic. "Impudent behaviour" towards Russia may have "nuclear" consequences, he said.
"A Russian takes a long time to harness a horse, but then rides fast," said the news anchor, quoting a famous Russian saying.
By "riding fast", Kiselyov was referring to a string of recent Russian military deployments:
- Last week, Moscow sent three warships from the Black Sea Fleet to the Mediterranean: on board, cruise missiles that can carry nuclear warheads
- Russia deployed nuclear-capable Iskander-M missiles into the Kaliningrad region bordering Poland
- Russia announced it would send several hundred paratroopers to Egypt for military exercises
- Moscow also suspended three nuclear agreements with the United States
Kiselyov said that in recent days there had been a "radical change' in the US-Russian relationship.
Moscow was taking action, he said, because of "the loud talk in Washington of a 'Plan B' for Syria. Everyone understands what this plan means: direct military force in Syria against President Assad's forces and the Russian military".
In Washington, the US state department said last week it was continuing internal deliberations about "non-diplomatic" options regarding the war in Syria.
In News of the Week, a Russian defence ministry spokesman warned American bombers not to target the Syrian army. Kiselyov put it more bluntly: "We'll shoot them down," he explained.
Is this bravado? Bluffing? Or is there a real danger of a direct military confrontation between Russia and the US?
In recent days several Russian newspapers have been talking openly about the possibility of such a clash.
"There is a reason that Russia has deployed S-300 surface-to-air missile systems to Syria," Izvestia commented last week.
"Moscow is ready to use them. This won't spark a world war. After all, we've shot down American planes before, in Vietnam and Korea [in Soviet times]. Vladimir Putin is making it clear that Russia will make no more concessions [in Syria]."
And Fyodor Lukyanov, Editor-in-Chief of Russia in Global Affairs warned that "this is the most dangerous situation since the Cold War".
"In the Cold War, confrontation was based on understanding of 'red lines'. Today this is not the case.
"Most likely no-one wants to launch a big collision between Russia and the United States. But this is exactly the case when unintended consequences might emerge."
To some in Moscow, Russia is merely reacting to Western aggression.
"There is a campaign to hit Russia everywhere possible," believes retired Lt Gen Yevgeny Buzhinsky. He cites Western sanctions against Moscow and even the banning of Russia's Paralympic team over doping allegations.
"Of course there is a reaction. As far as Russia sees it, as Putin sees it, it is full-scale confrontation on all fronts. If you want a confrontation, you'll get one.
"But it won't be a confrontation that doesn't harm the interests of the United States. You want a confrontation, you'll get one everywhere."