On 25 December 1991, Mikhail Gorbachev, the leader of the Soviet UnionOfficially the Union of Soviet Socialist Republics (USSR). A powerful group of communist republics, the biggest being Russia, that existed from 1922 to 1991. , addressed the people of this vast empire for the last time: "We are now living in a new world".

Overnight, a superpower spanning 22.4 million square km and counting 290 million citizens disappeared. The Cold War was over.

Thirty years later, history has come crashing back. On Thursday morning, Russian president Vladimir Putin ordered his tanks to attack Ukraine. By Saturday, missiles were hitting the capital of Kyiv. Yesterday, fighting broke out in the streets of Ukraine's second city, KharkivUkraine's second-largest city. Before the war, it had a population of 1.5 million.. Hundreds of Ukrainians have been killed and more than 120,000 have fled the country.

So far, the Russian army has been frustrated. Reports suggest that the defence has been stronger than expected. But for Putin, this might not matter. Many believe he will not stop until the USSR is back on the map.

This is an alarming prospect. The USSR was founded in 1917 by a group of revolutionaries. They wanted to overthrow the tyranny of the Tsars and create a new state where wealth was shared.

Things did not quite turn out that way. Vladimir Lenin's government quickly became a totalitarian dictatorship. Under him and his successor Joseph Stalin, the USSR and its agents committed numerous atrocities.

The KGB spied on Soviet citizens. Dissenters were killed or sentenced to work in bone-crushing labour camps. Between August 1936 and March 1938, Stalin ordered the execution of up to 1.2 million political opponents and ethnic minorities. 

Religion was banned and poverty was rampant. Millions of Ukrainians died in a famine between 1932 and 1933. 

Things softened under Stalin's successor Nikolai Khrushchev - but only a little. In 1956 he sent tanks to crush protestors in Hungary. And in 1962 brought the world to the brink of nuclear war during the Cuban Missile CrisisA confrontation between the US and the Soviet Union that occurred after the USSR installed missiles on the island of Cuba, within 140km of Florida..

Many breathed a sigh of relief when the USSR finally collapsed. But in Russia, the picture is more complicated. A 2020 poll found that 75% of Russians consider the Soviet Union the "greatest time" in their country's history - though only 28% want to return to it.

Putin once said: "Whoever does not miss the Soviet Union has no heart. Whoever wants it back has no brain." Today, some would argue he is acting with his heart. 

In the past decade, he has made a series of threatening moves against his ex-Soviet neighbours. He has also brought back USSR-style oppression, with protestors and political opponents arrested. 

The strategy is reminiscent of that pursued by the Soviet Union, but expert Kathryn Stoner points out one crucial difference: "It's not about ideology, just money and mutual convenience" she said.

And it might be difficult to replicate the USSR today. Three former Soviets - Estonia, Latvia and Lithuania - are now part of the EU and NATOThe North Atlantic Treaty Organisation was founded in 1949 to unite Western democracies in Europe and North America against the perceived growing threat of the USSR. It now has 31 members.. To absorb them would risk nuclear war.

The Iron CurtainA political, military and ideological barrier dividing Europe into two separate areas from the end of World War Two until the end of the Cold War in 1991.  was almost impenetrable. Soviet citizens were kept ignorant of life outside. It is difficult to achieve such isolation in the internet age, where anything can be filmed and broadcast globally.

Yes: Putin will not call his state the Soviet Union. But his invasion of Ukraine and recent aggressive behaviour towards ex-Soviet neighbours shows he is hungry for a new Russian empire.

No: The Soviets were revolutionaries. They sought originally to free people from tyranny and inequality. Putin's state has no noble ambitions whatsoever. 

Or... Russia is badly run, impoverished and increasingly irrelevant on the global stage. Even if a new Soviet Union arises, it will be a mere shadow of its fearsome former self, liable to crumble quickly. 

Soviet Union - Officially the Union of Soviet Socialist Republics (USSR). A powerful group of communist republics, the biggest being Russia, that existed from 1922 to 1991.

Kharkiv - Ukraine's second-largest city. Before the war, it had a population of 1.5 million.

Cuban Missile Crisis - A confrontation between the US and the Soviet Union that occurred after the USSR installed missiles on the island of Cuba, within 140km of Florida.

Nato - The North Atlantic Treaty Organisation was founded in 1949 to unite Western democracies in Europe and North America against the perceived growing threat of the USSR. It now has 31 members.

Iron Curtain - A political, military and ideological barrier dividing Europe into two separate areas from the end of World War Two until the end of the Cold War in 1991.