Ukraine war:By saying they have 'the means to respond', Putin has made a clear threat to widen war on Ukraine

How worried should we be by Vladimir Putin's latest chilling threat of a different kind of war delivered on a key anniversary for Russians - the 80th anniversary of their victory at Stalingrad over Germany? 

"Those who hope to defeat Russia on the battlefield do not understand, it seems, that a modern war with Russia will be very different for them", President Putin said in the city, now called Volgograd.

Ukraine news live: Kremlin rejects reports of secret CIA peace deal as a 'hoax'

"We are not sending our tanks to their borders, but we have the means to respond. It won't be limited to the use of armoured hardware. Everyone must understand this."

The comments are clearly a threat to widen the war and are being seen by some as yet another thinly veiled threat to use tactical nuclear weapons.

The Russian leader has rattled his nuclear sabre repeatedly in recent months, although western officials believe, for now, the threats ring hollow.

America's ambassador to NATO, Julianne Smith, repeated that scepticism in an interview with Sky News this week although she said Putin's threats are causing 'great concern'.

"We've messaged Moscow on this. But I think what we haven't seen is really any indication in recent months that they're preparing to use nuclear weapons.

"We're taking it seriously but I think right now we're not seeing any indication that they're going to make a move in that regard."

But pressed on Putin's words in Volgograd, his spokesman, Dmitri Peskov, told reporters: "As new weapons are delivered by the collective West, Russia will make greater use of its potential to respond."

He was referring to the modern battle tanks being sent to Ukraine by Germany, the US and UK.

Russian state TV propagandists have spent the week furiously comparing today's German leaders to Nazis in absurd hyperbole.

In Volgograd President Putin picked up their cue: "It's unbelievable but true. We are again being threatened by German Leopard tanks. Again and again we are forced to repel the aggression of the collective West."

And that is a recurring theme now among Russian propagandists, who claim that from Napoleon Bonaparte to Hitler to NATO today, the West has been on a centuries long campaign to destroy Russia.

One Kremlin mouthpiece even accused the Allies of colluding with Nazi Germany to attack Russia, in a grotesque perversion of history.

But the comments resonate with ordinary Russians. Russia is a vast diverse country. Its people have little in common. They have no shared belief in a system of government, ideology, or rule of law to bind them together. But as commentators have observed, they do all share a pride in their wartime defeat of Nazi Germany.

Putin and his propagandists may sound absurd to Western ears, but in Russia the constant reference to the victories over the Nazis carries weight and he hopes will help rally support for his failing war.

In the city where Russians won one of the greatest and most costly wartime victories, their leader seemed to be preparing them for far greater sacrifice in a war with no end in sight.

Western officials had hoped their sanctions, Ukraine's successes on the battlefield and Russian casualties now well over 100,000 would have encouraged Vladimir Putin to have a change of heart as we approach the anniversary of his calamitous invasion.

Far from it. He seems to be doubling down.