For two decades, the world has been living with the consequences of events in 1989. As well as the changes in Eastern Europe, the Cold War was winding down.
BBC Diplomatic Editor Brian Hanrahan, who has spent the year assessing 1989’s legacy, looks at what happened next.
The hard men of the KGB were glued to the TV screen. Upstairs, President Ronald Reagan and Soviet leader Mikhail Gorbachev were dealing with great power confrontation.
But down in the basement, Mr Gorbachev’s protection detail were watching a different confrontation - between Tom and Jerry.
Behind them smoke started to emerge from the wastepaper basket where one had dropped his cigarette - but they were so engrossed in the Western decadence they were sworn to protect against that nobody noticed.
The all-wooden building would have gone up in flames if the sharp nosed Icelandic caretaker had not ignored diplomatic protocol and stepped into the Soviet sanctum to douse the flames.
So was saved the Hofti House, and the Reykjavik summit in Oct 1986. And America and the Soviet Union were on their way to ending the Cold War.
Another backstairs story from that summit is about the direct telephone line installed to Moscow.
After Mr Gorbachev sprang a surprise with a disarmament package, President Reagan put a counter proposal - much to the concern of his aides because none of this had been anticipated or approved by the president’s advisers.
Buried at sea
Mr Gorbachev went off to phone Moscow and returned shaking his head. He was still a comparatively new leader of the Communist Party and could not make deals without the approval of the Politburo.
But fast-forward three years to the Malta summit and we meet a much more confident Mr Gorbachev. In December 1989, he agreed with Reagan’s successor, President George Bush, to move from confrontation to co-operation.
The Cold War was dead and, in the words of Mr Gorbachev’s spokesman, “buried at the bottom of the Mediterranean Sea”.
All through 1989 there were two separate processes going on - both brought about by Mr Gorbachev’s reforms.
One was the release from Soviet control of Eastern Europe - an explosive, headline-grabbing joyride for everyone involved.
The other was the quieter revolution in relations between East and West - the winding down of the ideological confrontation which for four decades had threatened the world with nuclear annihilation.
This was the real prize for Western leaders and they worried that a gleeful response to the liberation of Eastern Europe could put Mr Gorbachev’s position as Soviet leader at risk.
“We couldn’t be sure when the Berlin Wall came down that the Cold War would end,” says James Baker, who was the US secretary of state at the Malta summit.
“And that’s why President Bush was absolutely right when he would not ‘dance on the wall’ the way a lot of people wanted.”
Mr Baker says “by not sticking it in the eye to the Soviets”, President Bush made it possible for Mr Gorbachev to foreswear using force to hold the Soviet empire together.
“And he was right. He said: ‘We’ve got a lot of unfinished business with the Soviets.’”
Mr Gorbachev had created a window in Soviet thinking - a window to a more peaceful world. But Western leaders feared it would close if Mr Gorbachev was toppled.
Well of bitterness
In the years that followed, a see-saw battle broke out between the conservatives and the reformers within the Soviet leadership.
Mr Gorbachev struggled to balance himself as the changes which had started in Eastern Europe spread into the Soviet Union itself.
Lord Hurd, who was then the British foreign secretary, says: “It was inevitable. Mr Gorbachev could not be making these changes, these concessions, without criticism, without harsh debates.”
The Soviet Union was being asked to relinquish territory it considered part of its status as a superpower - occupation zones, military bases, buffer territories.
“It had been fought over,” says Lord Hurd. “It was full of memorials and cemeteries. There was no way that could be abandoned without a huge amount of bitterness inside the former imperial power.”
Although Mr Gorbachev was losing power, he held back attempts by the hardliners to revert to the repression which had been characteristic of communist rule.
Without its prison camps and an occasional massacre, the system could not sustain itself.
The hardliners judged, rightly, that what was at stake was the survival of the country itself.
But by the time they moved against Mr Gorbachev they were too late.
The Communist Party which had held the country together was no longer the central source of authority.
Their coup of August 1991 was easily seen off by the reformers under Boris Yeltsin, the new Russian leader.
What developed next was a free-for-all as the leaders of the nations emerging from the Soviet Union grabbed power for themselves.
According to Leonid Kravchuk, who was to become Ukraine’s leader, Boris Yeltsin’s first thought was to preserve the Soviet Union and replace Mr Gorbachev as leader.
Only after Mr Kravchuk insisted on independence for Ukraine did Yeltsin switch to the idea of splitting the country into separate states. It is a decision that still rankles with many Russians.
Much of the difficulties in dealing with Russia over the past two decades stem from its self-image as a superpower which ought to be pre-eminent among its neighbours.
But for the other states independence means the power to choose for themselves how close they should be to Russia. It still has not been resolved.
Leonid Kravchuk, the man who says he put Russia in to this position, was a former communist who reinvented himself as a nationalist.
He was in the group that negotiated the splitting-up of the Soviet Union. He remembers Mr Gorbachev’s surprise.
“He looked lost,” recalls Mr Kravchuk. “For him, like for everyone else, it was so sudden.”
He believes Mr Gorbachev did not grasp how history was unfolding, and will be punished by it.
“I think that in history Gorbachev will not be remembered as a creator, but as the destroyer of the Soviet Union because that’s what he did,” says Mr Kravchuk.
“I am the creator of Ukraine - in history. Yeltsin is the creator of new Russia - in history. And Gorbachev did not create a new union, but destroyed it.”
Delayed by Christmas
But outside the old Soviet Union, there will be a kinder judgment. Lord Hurd thinks Mr Gorbachev was well aware of what he was doing.
“We owe Gorbachev a huge debt. He loosened and, in the end, helped to destroy a system, and an antagonism with us, which had paralysed the world in many respects for a generation.
“And he did it largely through his own courage and a perception that the system couldn’t last.”
Mr Gorbachev did make one concession to save his place in history. He had intended to relinquish the office of Soviet president on 24 December.
But his horrified press aide, Andrei Grachev, reminded him that in most of the world the following day was Christmas Day. There would be no newspapers to record his going.
So the Soviet Union - rooted in atheism - survived an extra day to accommodate the Western Christian calendar.