In a piece for the Washington Post, Professor Sam Greene said Mr Putin’s track record as Russian president pointed towards a preference for his own short-term survival over longer-term ideals, while noting that a full-scale invasion of Ukraine was unlikely to be popular with voters at home.

But, Prof Greene added, Mr Putin had long spoken of a desire to see Ukraine and Russia united under one government and precedents had been set in the Russian president’s actions in Georgia and Crimea, short-term military incursions which had seen his popularity at home skyrocket.

With tens of thousands of Russian troops currently massed on the Ukrainian border, then, will the long-time Russian president sanction a new war?

Prof Greene, director of the King’s Russia Institute, said: “It is true that the annexation of Crimea gave Putin four years of stratospheric approval ratings of over 80 per cent, even as the Russian economy tanked. A large-scale invasion of Ukraine, however, would be very different.

“It would involve massive numbers of regular Russian troops, not a few thousand ‘little green men,’ proxies or mercenaries, and many of those troops would die. It would bring immediate and sweeping sanctions onto an economy that is already struggling to cope with the pandemic and inflation — at a time when 44 per cent of Russians already say the country is headed in the wrong direction.

“And however much Putin might believe that Russians and Ukrainians should share a government (presumably his), and no matter how much he talks about it on TV, only 17 pe rcent of his compatriots share that opinion. (Even fewer Ukrainians do.)

“Does that mean war is impossible? No. But if Putin does invade Ukraine, he will do it without broad public support at home, and in a manner that will almost certainly weaken that support still further. It would break just about every rule in a playbook that has ensured his political longevity.”

Read the piece in full here.