VLADIMIR Putin calls it “hysteria” but with 150,000 Russian troops on Ukraine’s doorstep and nuclear drills taking place this weekend across the border, there is nothing exaggerated about the fear now stalking eastern Europe.

Russia has been building up its forces on the Ukraine border since November, triggering Washington’s observation that they represent the "most significant military mobilisation" in Europe since WW2.

Together with pro-Moscow separatists in eastern Ukraine, the US calculates Russian forces now number up to 190,000.

Imagine if such a Nato force was parked on Russia’s border. Would Moscow blithely accept it as a harmless training exercise? I think not.

As western leaders gathered in Munich for the annual international security conference to discuss Moscow’s belligerence, tensions remain high that the feared invasion could take place any minute, any hour, any day. Russia has snubbed the gathering; the first time in 23 years.

To add to the threatening atmosphere, Putin has upped the rhetoric, accusing Ukraine of “systematic” human rights violations against the country’s Russian-speaking population.

Russian-backed separatist rebels in the Donetsk and Luhansk regions of eastern Ukraine said they were evacuating civilians to Russia’s Rostov region, even though there was no evidence a Ukrainian attack was imminent. Given almost half of Russia’s fighting formations are within 30 miles of the Ukraine border, it would be madness for Kyiv to launch a strike.

Nato believes Russia could use a “false flag” operation, a created incident or incidents, as a means to justify invading Ukraine.

Indeed, in the last few hours military activity is increasing with several incidents.

On Friday, a car-bomb exploded in the centre of Donetsk. It followed a missile attack a day earlier on a kindergarten, which each side blamed on the other.

Russian-backed authorities claimed they had intercepted a Ukrainian military squad allegedly trying to attack a chemical plant in the city of Horlivka.

Yesterday morning, Ukraine’s military command reported intense shelling from Russian-backed separatists against Ukrainian civilians. It released photos showing artillery strikes on the village of Novoluganskoe, in the Donetsk region.

In Moscow, attitudes are hardening. Vyacheslav Volodin, Speaker of the Russian Parliament, urged his Government to intervene to stop "genocide" and "crimes against humanity" supposedly perpetrated by Ukraine.

"Peaceful people are suffering, dying,” he declared. “We cannot stand idly by. We are concerned with defending Russian citizens and compatriots who live there. Kyiv’s crimes are being hushed up by Washington and Brussels.”

Yesterday, a pro-Russian separatist leader in eastern Ukraine ordered a full military mobilisation amid a spike in violence in the war-torn region of Donetsk, including the shelling of a humanitarian convoy.

It all looks like Moscow is getting its excuses in early and preparing the Russian people for an attack.

Kyiv insisted all of the Kremlin’s claims were pure “Russian disinformation” and insisted it was “fully committed to only a diplomatic conflict resolution”.

Worryingly, Joe Biden has said he is now “convinced” Putin has decided to move his military across the border, having spent weeks saying he thought the Russian leader was undecided.

Downing St is still open-minded about Putin’s intentions but one Whitehall source said: “He’s going to do it and it’s going to be horrendous.”

The US says the strength of Russian forces is not decreasing but increasing combined with assorted military hardware plus field hospitals, blood banks and pontoon bridges. Russian warships have been undergoing manoeuvres in the Black Sea off Crimea.

Washington said the announcement of Russian-speaking civilians being evacuated to Russia was another attempt by Moscow to “obscure through lies and disinformation that Russia is the aggressor in this conflict". An official claimed: "It is also cynical and cruel to use human beings as pawns to distract the world from the fact that Russia is building up its forces in preparation for an attack."

Yesterday, Russian state news agency pictures showed Putin from a command centre, observing the Grom drills, involving practice launches of intercontinental ballistic and Cruise missiles. It was a show of strength to remind people Russia remained a nuclear superpower.

It was, of course, straight out of North Korean leader Kim Jong-Un’s playbook.

Meanwhile, in Moscow’s strategy of coercive diplomacy, Andrei Kelin, the Russian ambassador to the UK, said he was “totally sure” war with Ukraine would be avoided. “Absolutely 100%, this will not happen,” he declared.

And yet, Kelin also pointed out todays’ end of the joint Russia-Belarus military drills was not assured if there were “provocations”, adding that he was sure any such tensions could be resolved by “negotiations” rather than fighting.

In Munich, Boris Johnson urged allies to show solidarity. He warned if Russia invaded Ukraine, the “shock will echo across the world”. The move would see the “destruction of a democratic state,” creating a “generation of bloodshed and misery”.

The PM admitted the “omens are grim” but insisted the “disaster” of a war in eastern Europe could still be averted by diplomatic means if the West spoke with “one voice”. Expect a Commons update tomorrow.

Kamala Harris, the US Vice-President, also in Bavaria to rally America’s allies, assured them of Washington’s “ironclad” support and made clear the consequence of a Russian invasion would be “swift and severe”.

Annalena Baerbock, the German foreign minister, made clear “all options” would be on the table if Russia launched an attack on Ukraine, including cutting the Nord Stream 2 pipeline deal that would bring Russian gas to Germany. Her country, she insisted, was ready to “pay a high economic price” for showing solidarity with its Nato allies.

Jens Stoltenberg, the alliance’s Secretary-General, warned the Kremlin: “If its aim is to have less Nato on its borders, it will only get more Nato. And if it wants to divide Nato, it will only get an even more united alliance.”

If Putin thought the West was weak and fractured, he may be about to learn he has made a terrible mistake and while Europe may pay a high price for his senseless aggression in Ukraine, Russia will ultimately pay an even higher one.